Fixing Hapy Furnace (part 2)

Picking up where I left off the last post, Hapy has an operational furnace again.

Fuel Pump Swap

As I mentioned in my last post, the fuel pump which originally delivered with the heater/furnace would not work when I tried to bring things back to life. I splurged and bought a more expensive "quiet" model for $50US rather than another standard pump for $20US. I figured quieter or not, the more expensive pump may have better parts in it, and it may last longer whether it is quieter or not. Or it was just a marketing gimmick and I got took. Let's chalk it up to the cost of an experiment.

The old fuel line path was relatively simple. The "hard" (clear but firm plastic) lines that delivered with the furnace had short (50mm / 2-inch) stretches of fuel hose between them and the pump. The pump was suspended from a cross beam by the included rubber mount held in place by a single sheet metal screw. After a few turns with a screwdriver, the pump was on the ground. A few more and the fuel lines were removed from it. The supply fuel line started dripping fuel after a few seconds, so I caught it with a pan. The line on the pressurized side was completely empty, so no drips. I simply reversed the removal: added the rubber mount from the supply end of the pump, added the supply fuel line, suspended the pump from the cross beam and then added the pressurized-side line.

Prime and Fire Up

The Afterburner has a control page where you can direct only the fuel pump to fire up. This allows you to get fuel all the way to the furnace without the glow plug turning on (drawing the battery and maybe burning out the glow plug). I had not connected the pressure line to the furnace, but I wanted to clear the lines of any bad fuel, so I moved the pan under the dangling hardline and triggered the Afterburner to prime. Within a minute of the prime starting, fuel started spurting out the end of the line. It took longer than I expected it to, but perhaps that is an indication of how little fuel these units actually consume. Once the fuel leaving the pressure line looked like the fuel supplied at a filling station, I stopped the prime function and connected the hardline to the fuel hose dangling from the furnace.

While the pump was slightly larger than the original, it did not seem much quieter during the prime. Of course, I hadn't heard it pump in a couple of years, and memory is a funny thing. I do recall that when the furnace was running, I could hear the tick-tick-tick of the fuel pump over the whoosh of the furnace. With this in mind, I set the furnace to start. I did not want to consider the experiment with the new thicker, dedicated wiring yet, so I left the battery tender hooked up. At no point did the battery fall below 13.5V so either the tender was working hard, or the new wiring is a hit.

Regardless, the glow plug got lit, the fan started spinning and after 2 or 3 minutes the furnace ignited. This felt like a considerably longer period of time than before. Perhaps the priming was incomplete and I needed to prime again after connecting the hose to the furnace. Perhaps it took time to ignite simply because it had been so long. Once it ignited, a huge plume of smoke poured out of the little muffler. There was virtually no wind, so the cloud grew and sat slowly obscuring first the rear end of the bus and slowly 2/3 of the bus before a light breeze broke it up. After a few minutes, the cloud dissipated and the exhaust emission was reduced to nothing. All that remained was a light smokey haze inside the bus. I regret not taking a picture of that.

Noise Observations

While the temperature inside the bus slowly crept up from 55*F (13*C), I noted the noises. I could only hear the fuel pump ticking inside the cabinet where the furnace is located and even then, only when I stuck my head into the cabinet. I think the pressurized line is transmitting it. I stuck my head into the rock-n-roll cabinet above the spot where pump is actually installed and could not hear it. Maybe this new pump is quieter. Then, I moved outside where in the past I could clearly hear the pump from several feet away, even from the passenger-door side. I could not hear it, but I could hear the furnace whoosh. Of course, my muffler-ing of the furnace is different this time, having removed the second small rectangular muffler and the motorbike muffler. Perhaps the pump is no quieter, but the furnace is that much louder. To determine if the muffler configuration is a variable, I decided I will conduct another test at a different time, after re-attaching the other muffler bits. I had thought about bringing them along for while-parked use, and maybe I will need to, out of respect for our festival-going neighbors. In the past, I took decibel readings, but they were for while the furnace held a temperature, not during temp catch-up (full blast).

I will continue to experiment with noise readings and post if I find any readings are different than they were 4 years ago. I expect that once I put the extra rectangular and motorbike mufflers on, the readings will be what they were before. The only real mystery to me is whether the fuel pump can be heard over it. At this point, though, the pump seems significantly quieter.

Thanks, as always, for following along-

Fixing Hapy Furnace (part 1)

Having finally arrived at a place where we have some heat while we're moving, I felt motivated to fix the heat for when we are standing still. Today's post covers most of the saga of getting a Chinese diesel heater operational again. Spoiler alert: the heater isn't running by the end of this post.

Brief History

Back in the early days of CoViD, I installed one of those Chinese diesel parking heaters into Hapy (See Parking Heater 1, 2, 3, 4, 5 and Final for deep detail). While I was able to run it a few times, I found that the heater pulled the voltage way down on whichever battery was connected to it. I tried to solve by providing multiple batteries to source from: one to start, one to run, but switching from battery to battery seemed like a bad practice. I had other priorities, so I just let the furnace sit unused. When I did the sound deadening effort and the luxury electrical re-wire, I dismantled the cabinet which housed the furnace so I could get sound deadener underneath it and electrical cables through it. This meant dismantling part of the furnace too. Later, when the band wanted to use Hapy for the album cover, I removed the furnace exhaust so it would not appear in pictures. So, I had a furnace without an exhaust, and would draw way too much juice.

Electrical

Over time, and with more learning about electrical stuff, I have concluded that the wire used to convey electricity but perhaps more importantly the wire for a ground were far too thin. It was due to these thin wires that the voltage would drop so badly as the furnace attempted to compensate. Wires which would have been barely up to the job had the battery been sitting right on top of the heater will definitely NOT be up to the task once you move the battery a few feet away. This is exacerbated by running the ground to the body of the bus instead of back to the battery. The ground location should not matter as much, but I'm citing it as a participant cause anyway. So, addressing the electrical came first after removing the furnace from the bus.

A small harness of wires leaves the furnace body and enters a black plug (see picture on the right). The harness that ships with the furnace includes a pigtail that clicks into the furnace black plug. To my eye, the red and black wires in the pigtail are not nearly as thick as the wires leaving the furnace. This probably saved the manufacturer a few pennies, but the amp draw issue starts right there (and in my case got worse). So, I cut the main power and main ground wires from the furnace black plug and put male/female wire ends on them (12V/ground respectively). I made them different so I couldn't accidentally plug it in backwards. I then prepped a thick 2-wire black/red cable with matching wire ends, and routed it over to the luxury battery. At the battery end, I added a ring terminal for the ground and added a 20Amp fuse into the positive side before adding a ring terminal on that end. I left things detached as I switched to preparing for the exhaust.

Exhaust

From under the bus, it was clear that I had not made the hole(s) large enough for the exhaust, intake and fuel to be easily maintained. Quite the contrary, I had installed it such that once it was all together, it would have to all come apart to fix anything. Frowny-face. So, I started by cutting a 4-inch square hole into the lower belly pan. Many buses do not have these, but I got lucky. Anyway, with the hole cut I could see where the furnace sat, and noticed that the exhaust was getting pinched by the too-small hole in the floor as the exhaust left the furnace. So, I went topside and expanded the upper hole both in the floor of the cabinet and the steel floor of the bus. With the larger hole, the exhaust easily fits and things could be maintained from below. Still, I did what I could on the furnace itself before lowering it in: Connect a 6" long stretch of fuel line, attach a small circle of window screen to the intake (so bugs and pebbles don't get in) and then attach maybe a foot of heat-wrapped exhaust. I set the furnace in place and attached a small subset of the muffler arrangement I had used before: just one rectangular muffler. I may bring the expanded muffler set up for use when we are in tighter camping spots (like festivals), so we can bolt-on some extra quiet. I mounted the muffler to the underside of the frame rail, with the outlet pointing rearward and slightly away from center (picture on the right).

A keen eye can see some fresh Rustoleum primer + paint above the muffler where I discovered some rust had eaten all the way through the body. When I was working on the other stuff I ground the metal down, removing the rust, but exposing the holes. Sadness. That rust traces back to when this bus had a small vent window directly above this spot. That vent window was badly leaking and the rust had already been forming to the point of marring the paint when I bought this bus over 20 years ago. I eliminated the vent window in 2015 (See Calling "glass") with a window I purchased from BusBoys in Redding, CA in 2009. Some things move slower than others.

Fuel

I shifted over to fueling at this point. The fuel line that had been between the included "hard" line and the furnace had breeched, probably when I did the sound deadening. The fuel in the line looked dark, so I dropped the line into an empty pail, and figured I would prime the fuel system, and purge the bad fuel at the same time. Unfortunately, the fuel pump is no longer functional, so I am waiting on a replacement to finish this job.

Afterburner

Back when I first did this job, I bought an Afterburner from the guy who hand builds them in Australia. Apparently, there are people building knock-offs, eating into his business, since they basically have cloned his work. So, if you are looking at getting the much nicer controller for your parking heater, please connect with Mr. Jones in Australia and get the real deal. Anyway, with the Afterburner, I tried to prime the fuel system, but the fuel pump wouldn't respond. When I unplugged the pump, I got a code; I concluded the wiring to the pump was good but pump was bad. So I ordered a new, supposedly quieter, one. We'll see. While I was clowning around with the Afterburner, I got it onto my home network, downloaded the newest firmware and wandered around the new-to-me website that the Afterburner hosts. It's really cool. I am looking forward to triggering the furnace to warm the bus from inside. For reference, here is a link to the user manual.

This is as far as I've gotten. I am waiting for a new fuel pump to arrive. I need to purge the old lines of nasty fuel, and install that new pump. I expect there will be other discoveries, and I need to rebuild the cabinet innards. There's always opportunities to improve things. Anyway, thanks, as always, for following along-

Hapy Heat Repeat (Part 2)

Continuing the efforts on creating some cabin heat in the old microbus, today's post covers sourcing the air for the heater from inside the bus.

Grounding

air sourcing from inside

In the last post on this topic, I mentioned that the prior attempts, and the original heat, for that matter, all pulled in air from the outside. The original heat pulled from the engine bay, sent it through heater-boxes (insulated boxes around the exhaust manifolds) and then up to the front of the bus. There was even a booster fan to push air when the engine speed was too low to push air. Years ago, I added a bilge-blower fan mid-stream to help get the air forward, and replaced large sections of pipe with insulated hose. In the end, the original system at-best, delivered warm moist air when it was raining (again, it's Oregon so that's 8 months of the year). When not-best, we got cold moist air that smelled like oil or exhaust.

When I did the ALH-TDI engine swap, I removed the original system rear of the front frame, setting a Vanagon rear-seat heater against that frame crossmember. While it didn't leak for a while, it started leaking again this past year. The unit was really never up to the task, and since it was only designed to heat the rear of a Vanagon cabin, I was probably asking too much of it. Still, it was a significant improvement over the original and bilge-blower-enhanced systems. The air was warmer more often, and exhaust-smelled less often. Overall, though, it was not "warm" in Hapy from the use of the heater, and the issue with moist air remained.

Fast forward to the Maradyne heater I just installed. Unlike the Vanagon rear-seat heater, the Maradyne is a 3-row heater core and it is almost twice the width. The core alone could provide considerably more heat. The fan is way more powerful too, so moving that heat into the cabin will be that much more  effective. What remained, however, is the air is still sourced from below the bus, so the wet roads will provide an endless supply of moist air to fling onto the inside of the windscreen. I hope I resolved that with the changes below.

Maradyne Heater Prep

purists love this

In the last post on this topic, I described how the heater was installed on an angle to minimize the ground clearance impact and so the outlets point more directly at the original air pipe. This orientation, however, meant that the brackets were hanging into the space where air intake hoses would go. So, first order of business was cutting those brackets down with the death-wheel (angle grinder). Once cleared, I could easily see that the coolant outlet jutted too far into the same air-hose space so I cut it down as well. Last, I changed the hose from the outlet from a straight hose to a 45* angled hose, routing the coolant above and away from the air inlet. While the inlet is not completely exposed now, it is considerably better. The inlets are 3" diameter and have a lip that's maybe 3/8" for a hose to fit onto. I had intended to add something more substantial for the hose to attach to, but once I got into it, I concluded that the original fan housing could hold a hose and clamp. Time will tell, and I am retaining the extensions I bought for this purpose in case I need to add them in later.

Holy Bus

Well, more like holey bus. In order to send air from inside the bus to the air intake on a fan system that is outside the bus, I need to add a hole or 2 for the air to pass through. I did not want to put air intakes in places where I would accidentally spill water (or other beverages), or get dirt and the like into it. I also did not want the air intakes to be so close to the front that the fan was effectively pulling the warm air right out of the outlet vents. I applied some cold-air-return thinking and chose to put one intake inside the rock-n-roll bed base cabinet. This cabinet is probably the coldest space in the bus (second only to my feet) and the vacuum created by the fan will draw air from the front to the back, creating room for the warmer air to enter the bus more freely. Of course, it's not like a 50+ year old microbus is sealed, but my 70+ year old house isn't either and once I tied the cold air intake into the house system, the house grew measurably warmer.

From underneath, I considered where there was a space without structure nor pipes to interfere with the air intake plumbing. With the radiator, wiring, original stuff and everything else, it is quite busy under there, but there is a space just behind the rear cross-frame (think: rear jack-point) but in front of the rear wheel well that is inside the cabinet, nearest the front outer edge. I tested a few spots with a drill to make sure that I could fit a 3-1/2" circle without hitting something neither underneath nor inside the cabinet and found a good spot. I cored a 3-1/2" hole with a hole saw. Why 3-1/2"? The inner diameter of these hoses is 3", and I felt that leaving a little extra room for wiggling was better than having it tight as would have been with a 3-1/4" hole. This turned out to be a wise decision. Once the hole was cut, I shot it and the support brackets with paint to delay (can it really be stopped when it rains 9 months of the year?) rust.

Fitting

cabin air intake

Once the hole was cut, I was on the home stretch. I found what look like air outlets with metal grills that fit a 3" hose to act as an air intake screen. I a-fixed one end of the hose to the grill, cable-tied it to be double-sure and passed the hose through the hole from above. The hose barely fit. It was so tight, I had to cut off the cable-tie because the cable tie end prevented the grill from sitting flat on the floor. Anyway, I chose an orientation that pointed the grill away from the center of the cabinet so things don't accidentally fall in or over it and then screwed it down to the wood floor of the cabinet. From underneath, I stretched out the compressed hose, stretching it along the side of the radiator, and turning it towards the fan.

I had initially planned to have 2 air intakes, one per fan intake, but after cutting the passenger-side hole, decided that I had 3" of outlet, so having only 3" of inlet was actually a fair balance. So, rather than run 2, I added a 3" wye along the passenger-side frame rail. I sent the stretched and then cut hose into the base of the wye and shifted to the fan inlet on the driver side, knowing it would be the harder of the two. I can always choose to add a driver-side inlet, but with the furnace on that side, there will be additional complexities.

The driver-side was definitely harder, but simply because the coolant outlet hose still ran across the air flow path. I twisted and bent the air hose and jammed it onto the inlet lip. I added a hose clamp while pressing the hose onto the lip, threading the clamp until it was quite secure. Content, I stretched out the hose, threading it behind the fan housing, but in front of the radiator intake to the passenger side. I added a cable-tie on the driver-side to hold the air hose in place. I cut and then sent the other end of the hose into the wye. It got another cable-tie up to the underside of the bus before it entered the wye.

The section from the passenger side air intake to the wye was a little over a foot, and was the easiest part of the install. I attached to the fan intake first, adding a hose clamp, of course. Once stretched and cut into the wye, I cable-tied the wye up near the floor of the bus, mostly out of sight. I cable-tied the passenger-side hose as well so there would be minimal pressure on the hose clamp. At this point, the air intake for the cabin "climate control" sourced from the inside of the bus.

Testing

ground clearance mostly unchanged

All that remained was testing the system, both for air flow as well as coolant. I started with the air flow, accepting that I could confirm that without running the engine. As expected, the fan blows hard, and draws through the inlet. Because the inlet is inside cabinet, it make less noise than it might have had it been placed elsewhere. Still, I will need to be aware of it when we pack things so it is not even remotely blocked.

Satisfied, I exposed the top of the engine and started it up. I had expected to simply add coolant/water while air bubbles appeared but 2 things interrupted that plan. First and worst, the injector pump started leaking all over the place. Now, to be fair, I had smelled diesel on my last couple of drives, so this was not 100% a surprise, but it still was a little bit. Second, air bubbles did not really appear. I will need to bleed the heater core segment, once I replace a seal or two in the injector pump. A seal set has been ordered, so until the kit arrives and is installed, Hapy will sit.

That's where we are at this point. I may try to bleed the heater while I wait for the seal kit, but it will depend on the weather and my workweek. Thanks, as always, for following along. More next time-

Hapy Update

Today I could continue the dissertation on the effort to move the furnace in our 1948 farmhouse. Instead, I actually have something car related... the check-in on Hapy that I said I was going to do in a prior post and then flat-forgot. Remember Hapy? He's the 1972 VW camperbus that launched this blog. I meant to post this yesterday, time got away from me.

Hapy No Start Returns

A few weeks ago, as the weather turned cold, Hapy became increasingly difficult to start. Again. I figured it was the same issue as last time (See Hapy No Start Again), and started checking things with my multi-meter. I started where the old problem was: the main fuse for the glow plugs. Nope, there's a clean over-12V signal there. Then, I checked the voltage at the relay, and it was fine there too. Same for the resistance in the wire and the fuse.. no issues. So, I started thinking about the glow plugs themselves. I swapped this set in when I put in the chipped CPU and bigger nozzles, but not because there was anything wrong with the ones that were in there. I had this set of plugs that I had lying around for a few years, and I was selling Flash. Flash had failing glow plugs (resistance tests between the plugs were not within a few ohms of each other). So, rather than put the new set into Flash, I got selfish and put Hapy's nothing-wrong-with-them plugs into Flash and installed the new-never-opened plugs into Hapy. Looking back, I don't think these plugs were nearly as good. I think we have had starting-while-cool problems from the beginning, but it was Summer when I did the swap and never thought about it. Until now.

I pulled the rear-most plug (#4?) and tested it by resting the glow plug threads against a grounded bit of steel on the engine and triggering the ignition to "run". After a 3 count, the tip of the plug started to glow orange. After another 3 count, I could hear the relay click off, and the tip returned to black. I did this a few times and each time it took a few seconds for the plug to respond and even then it was only the very tip. Based on some internet imagery, I concluded that those plugs were insufficient and bought a fresh set.

A few days prior to installing the new set, I started hitting the in-engine plugs with some Kroil penetrating oil at dinnertime. I did not want a plug to break off or damage the head during removal. Whether it was necessary or not, the plugs removed relatively easily. All of them had soot on them when they were removed. Into the trash they went. For each of the new ones, I applied some anti-seize onto the threads prior to installing and then only snugged them down (did not torque the snot out of them).

Unfortunately, my efforts to start Hapy when the glow plugs were not working did a number on the starter. Again. So, my attempt to start him after replacing the glow plugs was not fruitful. Since I did the glow plug swap around the furnace work, and the furnace still is not operational, I self-limited my time to just swapping the plugs and then getting back under the house. I returned the following weekend (bumming rides and car-sharing with Boo the week between) to remove and inspect the starter.

should be 1 part, not 2

I admit, I expected the starter to just need a remove / re-install cycle. I was wrong. This rebuilt starter was installed in June 2023. After a summer of being my "daily driver", the starter was cycled well less than 500 times. I guess rebuilt Bosch starters are not all the same. Maybe the starter was a Bosch but the rebuild was done with cheap-o parts, leaving just the case as a Bosch unit. Regardless, it did not take very long to notice that the seal on the end (which is supposed to go around the shaft which juts out when 12V is applied) wasn't there anymore. It had potato-chipped inside the little pocket where the nose of the starter goes. Neat! So, off to the internets I went looking for a suitable replacement. I decided to get a new one from MetalManParts. Run by MetalNerd, his site only sells things that he personally fabricated or installed into his own vehicle. I have purchased both types of things from him before and have no regrets. Since Bosch was sold off to Seg Automotive, he now supplies new starters from them. I trust that if he is selling them, he is using them.

Sadly, the install of a starter has become fairly rote, since I've done it so many times. I simply put a 19mm socket, 13mm socket, a ratchet and a couple extensions into my pocket, slide under the bus with the starter and it's installed in less than 15 minutes now. If the rear sway bar were not there, I could probably have it done half that time. Of course, I ran the battery down with all my glow plug testing, so it got a spell on the battery charger before I could test my handiwork. Once that was resolved, I turned the key to "run", counted to 6 (for the glow plugs, it's 45*F here) and returned the key to "off". I repeated and then tried to start. Fired right up! I let him run a few minutes to top off the battery and now he is back to being my daily driver.

Hapy Heat Not Heat

Remember all that effort I went through to install the Vanagon rear heater under the bus for some heat? While that was fun, the result is not much heat. I described the lack of warm on the drive to and from the Cascade Equinox festival. Beyond the lack of detectable warmth, opening the valve to try to get heat has resulted in a coolant leak. I can attribute no other source for why Hapy's coolant level is suddenly not holding. So, I turned the valve back off and will be replacing the Vanagon rear seat heater with something else: a Maradyne Fans Stoker heater.

Maradyne, but could be any

There are lots of auxiliary fans which all look the same and have the same spec's (300cfm, 40k BTU - airflow and heating capacity, respectively). JEGS has their own, for example, that looks identical. Since I am unsure who is the originator, I went with a manufacturer with a known, solid reputation. There is little documentation and hardly any photos of this particular unit on the interwebs, making this choice perhaps a little more risky. I find the 40k BTU number everyone is using to be gross hyperbole, but I don't know how to test that nor the 300cfm number. I will bench test to get some amp-draw numbers before I install it. The amp-draw might be useful information for the next person since even Maradyne doesn't list this detail on their product page. And, it could be one more thing that is exactly the same on all of these units. For future reference, the JEGS unit draws 5.5, 7.1 and 11.6 amps (for low, medium and high settings respectively). I had relays in-place for the medium and high draw switch positions for the Vanagon unit. I don't know if I  will re-use them. Perhaps the amp-draw numbers will help me decide.

One other thing to point out: none of these heaters ship with a coolant control valve. Since I was leveraging the valve in the Vanagon, I have to add one of these or the heat will be on maximum all the time. I included this "vintage" control valve in my order. I thought about going with an electric one, but decided that I would really like to re-use one of the big original heat-sliders on the dash to control the amount of coolant flowing into the heater core. That feels more authentic than another knob attached to the bottom of the dash. Of course, I haven't ever had that control cable, so I will be running this either full-on or full-off until I do.

For now, this means that trips in Hapy will be just like all the other trips I've ever made with him in the not-Summer. They will be cold. It will be like driving around in an ice-fishing shed, unless I can either install that heater soon-ish -OR- get the little Chinese diesel heater/furnace working.... or both. Since I do not have a garage and I barely have a 4-meter square piece of concrete to work on... and I have a house furnace to fix, I do not think Hapy's heat will get addressed terribly soon. At least I have the parts for when I do. Of course, now that he is my daily-driver again, I may decide another week without a furnace might be a fair trade for some heat, any heat, in Hapy.

That's it for today. Thanks, as always, for following along-

Hapy Heat Circle-Back

Brief post this week. I've been tearing down the electrical in the bus, and it's really not that photogenic. I'm not really sure how to post about it since it really is very boring from a read-all-about-it perspective. It does, however, take an incredible amount of time. I have spent probably 10 hours just slowly working through the circuits, figuring out what's what and then cutting and labeling things so I can put it all back together, but cleaner. So, while I figure out how to not bore people to tears, here's a quick update on the furnace.

Hapy outside townhouse
before Champoeg trip

As I post this, I am realizing that it was 10 years ago that my first marriage dissolved and, perhaps correspondingly, the TDI transplant really got legs. How time flies. Over the course of this next year, I will be hitting other 10-year milestones: getting my townhouse apartment (See Hey Strangers), that first camping trip with the boys to Champoeg State Park (See One Small Step for Van) in the TDI-powered bus, and meeting Boo (See Football, Friends and Further). Funny how 10 years later, we are still making improvements on Hapy, I am still fiddling with the TDI electrical and his exterior doesn't look much better. Where were we? Oh yeah, furnace fun.

 

Yeah Yeah, Follow the Manufacturer's Instructions

It's been a few months since I did the parking heater / camping heater install. As directed by the manufacturer, I have been turning the heater on and letting it run through it's cycles about every 6 weeks since. My last runs have been these last 2 weekends. 2 weeks ago, it was super cold (low 40*F's or ~5*C), so I thought it would be interesting to see how the heater sorted itself out. The heater had the interior of the bus genuinely warm in about 10 minutes.

 

Can't Leave Well Enough Alone

I thought I would experiment with the fuel pump frequency at the low end of the maintain cycle. This is the speed at which the heater would run when you achieved the target temperature. I figured that even at the recommended 1.3, the noise coming through could be disruptive when you're sleeping in the middle of nowhere. So, why not see if it can go super slow? So, I set it to 1, which is below the manufacturer's recommended low. I left the bus alone for a while to see if it could arrive at stasis. When I returned about an hour later, the inside of the bus was kind of exhausty-smelling. Yuck. I shut things down, and thought about whether I had an exhaust leak. I had not had that smell before, so either I hadn't run the tests long enough before, or maybe that manufacturer setting was related.

Not a Leak, Just a Bad Idea

Fast forward a week, and I'm ready to test again. This time, the temperature is just above freezing. I turned on the heater, using the built-in Afterburner WiFi, from my living room. This is so cool. So, I'm in my living room, and simply connect to the WiFi and go to 192.168.4.1 on a browser and bam, there's the controls for the heater. Tap on the thermostat image and a popup asks if you want to start the heater. Once that process started, I changed the fuel pump low setting back to 1.3. After about an hour, I checked the Afterburner browser on my phone. The heater was maintaining 68*F (20*C), and was in a maintain cycle running the fuel pump at 1.3. So, I put on my shoes and coat and went out to Hapy. No exhaust smell, just the smell of warm metal from the furnace. Of course it was totally comfy.

 

I now conclude that when you go below their recommendation, the heater still works, but I think the fan speed is somehow involved in the force at which the exhaust is expelled. Continuing this thought, since the fuel pump was set so low, the fan ran super slow, and the exhaust fumes built up inside the bus. Neat.

So, that's it for today. Basically, if you were wondering if you can run the heater at a setting below the manufacturer's recommendation, that answer is "yes", but the risk is not just premature wear. The greater, or at least more immediate, risk is that exhaust may not properly vent, so you could create an unsafe condition inside your bus. Thanks for following along-

Defrosting - Part 4

After that fun experiment, I really couldn't get myself back to sanding. So, today, I am going to talk through the electrical set up. I will eventually get back to sanding and Bondo, and more sanding and then primer... and more sanding...

12V and Grounding

routing wiring

Unlike my stereo installs, this time I started with the most basic of wiring: B+ (12V supply) and ground. For the supply-side, there was one remaining basic bladed fuse spot in the battery-top fuse location that wasn't already in use. I spliced a 12ga wire into that spot, and ran that wire along the other back-to-front wires along the passenger side. Leaving myself plenty of extra length, I stripped the end.

Then I switched over to the ground side. Again, with a 12ga wire, on one end I added a ring terminal and screwed it into the rear cross-beam where I have the radiator fans grounded. On the other end, I added a female spade connector. With these 2 wires, I tested the heater to make sure the fan would spin at different speeds based on which of the 3 male connectors was given 12V. First, of course, I added a 20A fuse into the bladed fuse spot. I felt this would work, since the heater unit worked before, but again, I probably could have tested this when the heater was freshly out of the bus and on the ground rather than waiting until it was installed, register constructed and installed, etc.

All 3 speeds work. While the fan was running I crawled out from under the bus and checked the air flow at the windscreen. I don't think the lowest speed will really be terribly useful, but the middle and upper speed should be sufficient to clear the screen, I think. Any of them will be better than the squeegee / towel method bus drivers usually use.

Control Wiring

finished view from underneath

Satisfied that the fan will work, I shifted over to how to control the fan. In my shelve of random stuff, I have about 10 meters of trailer wiring. This is a flat cable which contains 4 16ga wires. I felt that 16ga was too thin to carry the current for the middle and upper speed, but should not overheat for the lowest setting. After my findings above about the usefulness of the lowest setting, I'm not sure it will be used much anyway. So, my thought is that I will send 12V from the supply up to the fan switch through one wire and the signal for which speed will pass through the other 3:

Red - 12V
Black - low
White - mid
Green - hi

Similar to the cable I sent front-to-back for the gauges earlier, I sent this cable along the main harness, through the center belly pan and through a new hole I cut next to the other 2. I made sure this hole was fairly large (1/2-inch) so I could send a thicker control cable through that hole later. With the cable hanging on the emergency brake handle, I wired up the rear end. First, I removed about 4 inches of cable jacket so I could work with the wires individually.

To the Green and White wires in the flat cable, I attached female disconnects. I put together a pair of 12ga wires with female disconnects on either end, each wire is about 40 centimeters (15 inches) long. These will go from the relays to the fan for the mid and hi speeds. I put together a pair of 12V supply wires for the relays: each wire is about 10 centimeters (4 inches) long with a female disconnect on one end and a long (1cm) stripped end. The stripped ends were spliced together. These stripped ends were then fed into one end of a larger crimp-splice. Into the other end went the 12V source from the battery as well as the Red wire from the flat cable. I did something similar for the ground side, creating a pair of short wires that were then spliced into the ground for the heater. With all the wiring ready, it was time to plug in the relays.

Relays

these area a matched pair. Mine aren't

I was fortunate to have 2 12V automotive relays in my cache of electrical stuff. While they were both old Radio Shack relays, they were not identical so the pins had different arrangements of pins between them. Of course, my eyesight isn't that of a young man, so each pin was managed carefully. I started with the ground wires going to pin 85 and the signal wire going to pin 86. The 40cm wires connected to pin 87, with the other end going to their respective fan pin. Last, the 12V wires connected to pin 30.

These relays delivered with a mounting hole molded into the plastic housing, like the picture here. Most folks would send a screw through that hole and mount it into the body somewhere. Well, first, I guess I'm not most people and second, getting a drill up under the bus with a flat enough angle to put a hole through the crossbeam, and high enough to keep the wires up out of the air stream was simply not possible. So, instead, I ran a cable tie through, and zipped them up to one of the steel tubes running just under the floor. This held the relays up near the floor. Last, I wrapped the wiring with one of those plastic wire loom things so rather than seeing a bunch of wires hanging around, you only see one black cable.

I tested the relays before I moved on. I did that by simply jumping the 30 with the corresponding pin 86. Once the relay clicked and the fan spun up, I moved on.

Fan Switch

silver on the knob may be too shiny

With the fans all wired, I needed to put in a switch. I did not want to reuse the old vanagon rear heater switch again. I was unable to get it to mount well before, and there are so many viable alternative options out there. I went with a made-in-USA INDAK switch. These have a standard 1/4 inch shaft, but the threaded mounting shaft is slightly thicker than the standard hole in the bus dash. I had to expand the hole with a drill bit to 11mm. On the side that is buried within the dash, there are 5 pins, though I only need 4 of them. The extra one (labeled "C") is for powering a clutch or lighting a bulb to let you know the fan is on. I think we'll be able to figure out if the fan is on without a light. I wrapped that pin with heat shrink so it wouldn't accidentally short out. Of course, when I run the battery down because I forgot that the fan was on the low setting, I'll post about it. Hahaha. I checked the length of the flat cable and then added female disconnects to the 4 wires. Following the table above, I plugged in the switch.

pay no attention to the dangling wires

I ran one more set of tests to make sure the fans spun at the right speed for the various switch settings. Once satisfied, I slid the switch through the hole I had expanded earlier, threaded on the mounting nut, popped on the knob and called the electrical done. Hazah!

So, I guess that's kind of it for the defroster for now. I will improve the sourcing of the input air as well as add a control for the amount of coolant flowing into the heater core, but I don't know when I'll get to that. Frankly, the way I've been avoiding the Zed bodywork, it could start tomorrow. Hahaha...

Thanks, as always, for following along. Stay safe. Please wear your mask covering both your nose and your mouth (seriously people. that much should be obvious). A mask is not a political statement; it is to protect the people around you, whether you or they believe in CoViD-19 or not.

Defrosting - experiment

And so it continues. I think, when it comes right down to it, I don't want to do paint prep. Sanding sucks. I see why most people pay others to do this when they can. Ugh. So, I'm dodging it for another day and clowning on Hapy instead. Today, I hacked together something as an air intake for the defroster/heater. This was only an experiment, and a way to kill some time in the Summer sun.

Winter is Wet, Summer is Hot
With some nice weather settling in, I am finding pleasure in doing little things that do not involve getting super dusty from sanding. Or worse, getting super sweaty and then having sand-dust settle onto that sweat. So, instead, I did a semi-worthless effort on the heater/defroster. One of my ongoing concerns for this heater is that when I hit a puddle, the wet will hit the heater air intake and my windscreen will instantly fog up. I figured I could slap something together as an experiment to reduce that risk. So, off to the headed-to-the-dump pile I go.

Dumpster Diving, the Home Game

vent-hole end

The tipping fee at the dump seems to climb every year. They get you for, like $25US just to drive in, so we will usually queue a load and make a run to the dump once a year. This year, that pile includes an array of rusted car parts (big surprise) and a carpet cleaner that fell apart. That carpet cleaner provided me a couple of 1-1/4 inch diameter hoses to use as an air intake. I rinsed them out with the garden hose and let them dry in the sun while I figured out how to connect the hoses between the heater intake and some part of the bus.

Back to the pile. I found some 1-1/4 inch PVC pipe. This pipe fit perfectly inside the hoses, so I had the makings of hose bib's. I cut 4 3-inch lengths, and put the rest back in the dump pile. Why 4? Because I will use the hoses in parallel. Why? Because the air intake side of the Vanagon rear seat heater is designed such that one of the coolant lines runs straight across the intake. Back when I had this unit on the luxury battery tray I had added a flange to attach a 4" dryer vent hose, but I didn't have any dryer vent hose in the dump pile and I wanted to do this experiment with free stuff.

Last, I picked up the original bottom plate for the defroster heat register that I discarded in my last post about this defrost saga. I figured I could cut something up to go against the air intake out of that tin.

Hack, but Free

free supplies

The bus air system originally has a floor vent between the front seats that routes air back to the main cabin. There is a cable-controlled flap that Y's off of the main air pipe into a corregated hose. On Hapy, that hose was falling apart when I bought him, and the cable-controlled flap was rusted shut. So, I removed the hose, tapes off the openings at either end with that fancy metal HVAC tape and didn't think about it again. Until now. I thought I would try to source cabin air from that vent. The vent hole, however, is smaller than the combined 1-1/4 inch bibs. So, I cut a pair PVC pipes on an angle and super-glued the angled sides together so the narrowed end could fit into that vent hole.

On the other end, I cut up the discarded HVAC tin into a 4 inch circle with 2 1-1/4 inch holes in it that aligned with a gap between the coolant line and the edge of the flange. In an effort to just get it together, I attached the PVC pipes with glue and that metal HVAC tape. I do not expect this to last terribly long, but this was just to see if the idea was viable. Besides, this whole experiment was to get me out of sanding... No, that doesn't make sense, but don't throw logic at me. I am justifying why I'm not sanding. Anyway, I slid the hoses over the respective bibs, and now we have a means of testing whether we can motor through a puddle in cold weather and avoid fogging the windshield.

Next Time

inlet side hack

Truth-be-told, I will probably be getting some dryer venting for the house anyway, so I'll just buy a meter more than I need for the house. There is a hole in the driver-side belly pan around which I can attach a flange. I should be able to fit a hose, albeit wedged up and folded by the coolant line, onto the flange on the heater, and connect that to the flange I add to the belly pan. Regardless, this was a fun experiment, and kept my hands and brain busy on an otherwise lazy summer Saturday during the CoVid-19 safer-at-home period.

Thanks for following along. I might do something more constructive next time I avoid sanding. Or, I'll actually do the sanding and my next post will be about an old trip or the threat to humanity currently occupying the white house or maybe (shock!) I'll actually post about sanding. Nah, that would not be interesting reading. Stay safe, stay physically distant and please consider that you wear a mask to protect others regardless of their politics. Or yours.

Defrosting - Part 3

I have spent the better part of my free time over the last several weeks sanding and hammering on the Zed. If you do that long enough, eventually you need a break, to focus on something else. Otherwise, you'll lose interest in the job, or maybe working on cars in general, and find yourself taking a few weeks off, like I did last winter when I did the TDI retrospectives. I just didn't feel like working on my cars and the weather was crappy, so motivation was at a premium. Anyway, today's post collects together the bits and pieces of hours I've spent taking a break from the sanding to move one little step forward on Hapy's defroster.

Model First

model from p-side rear

One thing I've learned along the way is to model what you want to build before you built it. With the speakerbox I built for Oliver (the MGB), I built a box out of cardboard first, That allowed me to really understand how it could fit before I started cutting MDF. I did the same thing for the heat register in Hapy when I did the parking heater. So, it should come as no surprise that I built a model of the defroster register with cardboard before starting in on the zinc-coated steel.

This had some aspects that were similar to the parking heater register: I needed to connect a round inlet/outlet with a rectangular inlet/outlet. That is about where the similarity ended, though. The space I had available, and the means of accessing that space made the design of this register quite different.

Piecing It Together

model from d-side rear

I started with a top-plate that matched the 9" wide heater, with 2 partial sides that dropped about 3 inches on each side. This is a simple rectangle with 2 90* bends. For the bottom I tried a trapezoid shape, with a large rectangle in the center, aligning the 9" bottom of the heater with the bottom of the front cross-support bottom. The sides are triangles that bend upwards, overlapping with the 2 sides dropping from the top. These two pieces would be held together with sheet metal screws, and the seams taped with the same contractor-grade metal HVAC tape. This shape is obvious, but it does not route the air towards the round hole. It just compresses the air from a 9" by 6" rectangle to a 9" by 3" rectangle. I figured there would probably be significant air turbulence, reducing the actual air-flow down the pipe to the floor or windscreen.

To reduce the turbulence, and improve the air flow, I added 2 trapezoid-shaped angled sides. Three straight sections were parallel to the heater face and the cross-beam as well as along the top. The one the angled side runs along the bottom from the lower edge of the heater to the lower edge of the cross-beam, just to the side of the round hole. Now, this still wasn't perfect, since the register now ends in a square, around the round hole. I figured this was the best amateur register I could come up with.

Install Planning

nutria and ducks in harmony

Finishing the model took many trips under the bus, fitting and then sliding back out to trim or add material (blue tape). Once I had the piece constructed so I could fit it into place, I needed to figure out how to install it such that I could assemble it in-situ, but could disassemble it and remove it when necessary. Note I didn't say "if"; it's wise to assume that you will need to undo something or you are just making life difficult for your future you.

The top plate was fairly straight forward. It could go in independently, simply by tipping the front (front is front) downward and sliding the rear edge up and over the top of the heater, rotating the front into place and then settling the plate down. The bottom was similarly easy, just offer it up. The challenge was with the angled side-runs.

I had considered pop-riveting the side-runs to the top in-place. This would have been difficult to undo for removal, so I planned on sheet metal screws instead. The side-runs got extra tabs along the top and bottom through which I drilled a pair of holes in each. These holes aligned to holes in the top and bottom so I could screw the side plates first into the top and then into the bottom.

Build and Fit

model to tin

Once I had it all working with a cardboard model, I transferred the lines to the zinc-coated HVAC sheet metal and cut the lines with tin-snips. As could be expected, the lines weren't perfect and some additional fitting was necessary. In fact, I abandoned large parts of the model entirely to get it to fit. First, getting the angled sides to fit in-situ with screws was simply not going to happen. Second, and more important, the cardboard model had flex to it that belied the fit. So, I abandoned the screws and held the sides to the top with that really good metal HVAC tape on both sides. I also used this tape to hold the front of the top section to the cross-beam.

Then, the real fun began. The bottom plate did not fit; at least not on the passenger side. I am not sure how, but the passenger side ended up about 25mm too long. It was just off. Again, I credit the flexibility of the cardboard during the modelling. Boo had asked why I had retained the fuller size of the bottom, stretching all the way across the whole span, when the sides really abbreviated how much I would really need. This is why working in groups is so powerful. Taking her advice, I modeled a new trapezoid-shaped bottom out of cardboard that would fit between the sides, front and back. I transferred to the flashing a cardboard cut up of a new bottom. Again, I used the metal HVAC tape to attach the sides to the bottom as well as the front and back. While this isn't as "perfect", the goal will still be met: air flow from heater/defroster will route into the original air pipe. With careful use of tape, I was able to have only the silver part of the tape visible from the sides.

When I can't take the body-work any longer, I will look into running the wiring and switch for the defroster fan. I'll post when I get to it. I did test the register by running a fused 12V source to the heater unit (and grounding the heater). The register had a couple small leaks that were easily fixed with more metal HVAC tape. That stuff is magical.
Thanks, as always, for following along--

Defrosting - Part 2

First, happy belated Summer Solstice. Our annual pilgrimage to Bend for 4Peaks which usually coincides with Summer Solstice and Father's Day was thwarted by CoViD this year. So, we are taking the side-lining as an opportunity to fix or upgrade things on the bus that are just too hard to do in the cold and rain. It seems with every improvement, I discover 2 more opportunities. Today (hopefully) begins the end of the defrost epic. In my last post about the defroster, I provided background. Today, I get started on the plan I described.

Tear Down
While I had disconnected the electrical from the Vanagon rear heater a while back, the coolant lines were still hooked up. So, my first step to removing it was unhooking those hoses. The clamps are easy enough to loosen with a Phillips screwdriver, and I was able to back the hoses off the barbs with a slotted screwdriver. With each one, I quickly moved the hose end into a clean bucket to catch the coolant. Once the lines and the heater were drained, I could extricate the heater unit from the shelf. With all of the wires and cables, this took a few minutes, and the resulting empty shelf doesn't look much better. Quite the contrary, actually, but, it does create a much better space for me to re-arrange the wiring one day. Yeay, more work.

Defroster Placement

valve shown closed

With the Vanagon rear heater in-hand, I could try out some ideas for how to fit it under the bus. The radiator sits just in front of the rear cross-beam, leaving a little over a foot between the front edge and the front cross beam. It is into this small window that the heater will fit. I held it up and thought about my options. If held right-side up with the front edge of the heater parallel to the cross beams, the coolant barbs would be facing rearward on the passenger side and the mounting tabs would be on the bottom. There looked to be enough space in front for a cowling or register to be put so the approximately 9" by 6" rectangular box could winnow down to the 3" diameter circle of the old air channel. The angles would be kind of sharp, but the air flow would be direct.

If the heater unit was turned sideways, the barbs would face the driver side. The air would need to make a hard left and it didn't look like there would be much space. So, I rejected that orientation.

I tried flipping the heater upside down, back in the parallel-to-the-front-beam position. Like this, the barbs were still on the driver side, but facing rearward. Since the coolant lines leaving the engine were also on the driver side, this was preferable. The drawback to this set up is that the bleeder screw is on the bottom, not the top. So, getting the air out of the system could be more difficult. In contrast, though, the mounting tabs were now on the top, so any attachment would be greatly simplified. The simple attachment won the decision. In this orientation, the valve for allowing / preventing coolant into the heater core was also on the driver side, sliding forward and aft for open and closed (respectively).

Defroster Mounting

safety hole drilled

Before I could consider routing coolant and air, the rear heater needed to be attached. The mount holes are exactly 7" apart. So, I found the centerpoint in the air pipe and measured 3-1/2" out from each. I aligned the heater on those lines and pushed it as far rearward as I could before it touched the debris-grill on the radiator. My thought was that the more gentle the angles in the air register, the more easily air would flow into the old pipe. As is, the front of the heater is about 4" back from the front cross-beam. Once the spots were marked, I drilled 2 holes through the floor. Through these holes, I sent a pair of 2" long bolts. From below, I nutted down against the floor with a pair of nuts, then added another pair less than 1/2" from the ends. I slid the heater unit onto the bolts and then nutted it down with another pair of nuts. So, that's bolt head | floor | nut - some space - nut | heater | nut. I put some threadlock on the bolts. Before I added the heater, I set an extra (safety) hole through the mounting tabs. Through this hole I sent a cable-tie, and then looped each side up to the pipe that the transmission shifter runs through. I figured that if the nuts found some way to work themselves free, the cable ties would hold the heater until I discovered and fixed it. Figure, the likelihood of both nuts coming loose and both cable-ties breaking before I realize something's up is fairly remote.

Get Hosed

"defroster unit" installed

From the engine to the Vanagon rear heater / bus defroster is a stretch of a little less than 8 feet. From the prior install, I have 1 meter lengths of 5/8" hose attached to the outlet and inlets, draped into a bucket of shallow coolant. I did a little research and learned that the Vanagon had 5/8" hoses, but there was a section of hose or pipe through the firewall that was only 1/2". There is also a restrictor of some kind that reduces the coolant flow to the rear heater. The theory is that if the rear and front heater units present the same diameter, the coolant will take the shorter path (rear heater), leaving the front of the Vanagon wanting. Well, we don't need the restrictor, but we can use the 1/2" pipe concept. I figure if the original can handle the smaller pipe, and deliver coolant without a pressure issue, we can use the smaller diameter pipe, potentially getting the coolant to the defroster faster. Maybe it will stay that little bit warmer. Ultimately, I had 1/2" pipe and I didn't have 5/8" pipe, so maybe I'm just back-justifying.

pipes in, hoses started

Aaanyway, I cut 2 33" lengths of 1/2" aluminum pipe, wrapped them with pipe insulation and mounted them to the underside of the driver-side belly pan, at least 6" inboard of the diesel heater exhaust. For mounts, I used 1/2" pipe hangers threaded into the bottom of the pan with long Phillips head sheet metal screws. Onto each end of the 1/2" aluminum pipes, I added a short stretch of 1/2" hose, and then a 1/2" -to- 5/8" reducer. At the rear-end (front is front), I attached the 5/8" hoses that were hanging in the bucket, previously used to route coolant from the engine to the heater. At the front end, I ran a stretch of 5/8" from the engine-outlet side to the lower barb, and the upper barb to the engine-inlet side. My thinking was that if there were an air bubble, it would be forced through and back to the engine... or at least down to the bleeder screw. On that, I have been considering how to thread in a short stretch of hose into the bleeder threads in thinking that I could raise the other end above the heater core for bleeding. I haven't pieced that all together yet.

I'll stop here for now. I did fill the system with coolant, opening the various bleeders along the way. I burped out air and then ran the engine for a while trying to get any other air out. We'll see how effective I was. As is, Hapy is drive-able again, with a completely closed cooling system. Next, I need to tackle the register, connecting the heater to the air duct and then wiring up the fan.

As we get deeper into the summer, this project seems less important, but fall feels right around the corner. If we ever get to see live music again, or simply camp in a State Park, having a means of clearing the windscreen hasn't a season here in the Pacific Northwest where the dew point is usually only a few degrees away.

Thanks, as always, for following along. You don't need to believe in CoViD-19 to catch it; you just need to be careless, or be around others who are. Please continue to wear a mask, wash your hands and practice physical distancing for the better health of those around you--

Defrosting - Part 1

No, this post isn't about how to remove frosting from a cupcake or the like. Today's post (and, knowing me, the next several) is a return to the seemingly never-ending effort to clear the windscreen on the old VW bus.

Modern Set-Up

It probably makes sense to start at the beginning. Most folks who drive modern cars do not realize how spoiled they are. The engine is sitting right in front of you, and it is water-cooled, providing a great source for warm air. The defroster system has relatively short hoses to move that coolant from the engine to the heater core inside the little plastic chamber (like the one pictured to the right here) below the windscreen. The heater core is controlled with short cables or little motors controlled from the dash, routing air through short channels into the cabin or up onto the windshield. In my more modern cars, I can push a button and fire up the air conditioner (A/C) and speed up the defrost even faster. You probably knew all that, but still it is important to have that context. One last little bit worth mentioning: the source of the outside air is usually right in front of the windshield up on top. This gives the highest probability of fresh air.

Original VW Bus Set-Up

from JBugs of a Beetle but you get
the basic idea

The bus is not at all like the modern car I just described. We start with the obvious: the engine is in the back and it is air-cooled. Back when these buses were new and before owners got their hands on them, the design of the heat/defrost system was relatively simple. The air cooled engine produces lots of heat, especially off the exhaust manifolds. This is a heat source for all cars, frankly, but the German engineers latched onto the exhaust manifolds for the cabin heat source. They did so by wrapping big metal sheets around the exhaust manifolds and called them "heater boxes". Air was driven through these heater boxes by the engine fan when the engine was running fast enough. Alternatively, there was a "booster" blower fan when the engine was not fast enough. The air was forced from the very rear of the bus through these boxes to a pair of controllers (one on each side) that were activated by a cable adjusted on the dashboard with a pair of levers (one lever per cable). From the controllers, corrugated tubes connected to a "Y" joint, then to a long central pipe up the center of the bus to the front. This picture on the right here shows a slightly different story for the Beetle, but the concept is very similar. At the bus driver's right foot there is a lever which directs the air either to the floor register or up to the windshield.

When it was originally constructed, I imagine that it worked quite well. Unfortunately for many bus owners this system is not typically well maintained. Parts are removed for "performance" reasons (heater boxes are often sacrificed), they deteriorate and fall off (corrugated tubes or air hoses from blower fan) or they just fail (cables). Often the various parts of the system do not connect together as well as they did originally, creating gaps. So, by the time a bus reached even 25 years old, many drivers would not get warm air when they manipulate the levers. Personally, the best I ever got was semi-warm oily-smelling damp air drifting thru the vent with zero urgency. Ultimately, my defroster was a squeegee and a towel I kept between the front seats. When it was cold, I would also keep an ice scraper.

There are many posts and threads about how to restore or improve these systems. The best advice is to start at the back and work your way forward, making sure everything is the way it is intended. Replace the seals, adjust the cables, lubricate the moving parts, etc.

Add-on Blowers

Atwood bilge blower

Years ago, I read a piece suggesting the addition of a 12V bilge blower to the mix of parts. The idea was that if you boosted the CFM, with a fan in the middle that you would get better performance. I found that the bilge blower just increased the rate at which the damp semi-warm oily smelling air appeared at my windshield, ultimately increasing the fog, rather than reducing it. At it's peak, I was able to reduce the damp (by letting the engine get super warm), but there was no way to prevent a flash-fog while driving in the rain and hitting a puddle. Also, no matter how long I ran the engine, once it was cold enough for ice to form, the bus could never get warm enough to keep ice from forming on the inside of the windshield. Now, this could in part be because of door and window seals, but even sitting still, with the bilge blower running with a hot engine the best I could do was hold the ice at bay.

So, I added a "parking heater". No, not like the one I just installed (here). This was a super small electric-coil based home space heater that I left plugged into the AC outlet inside the bus, under the rock-n-roll bed. When I was parked at home, I would run an extension cord under the garage door and plug it into the bus. An hour before I had to drive somewhere, I'd plug in the garage-end and pre-warm the bus. This worked for the morning drive to the mass transit parking lot, but the drive home was still quite cold. Icy windscreen at worst, foggy (queue squeegee/towel combo) most of the non-Summer months.

To help remedy the cold windshield, I got one of those accessory-plug fan things like in the picture here. For the drive home from the transit lot, I would point that thing at the windshield right in front of me. If I stayed at or below 25mph, I could keep a small circle in the center of the windshield clear enough for me to take the backroads home without having to resort to wiping the windshield with a towel. Needless to say, this was not exactly safe nor workable for the long term especially since I had to drive with one hand holding the thing, moving it around to make a big enough circle to see through.

First Defrost with TDI
When I did the TDI conversion, I thought "well, I'm finally gonna have some heat". 10 years later, my first defroster attempt was okay, but it still lacked. When my ignition melted a couple of years ago (See 4Peaks 2018 - Road Report), I thought maybe the fan set up was part of the problem so I ripped the electrical part out. Still, for perspective, it is worth describing what it was.

I bought a used Vanagon rear heater locally in Portland for, like, $20. I set it on the driver-side auxiliary battery tray (left side) and added lengths of 5/8" hose from the heater to the appropriate in/outlets on the TDI. I fab'd a register that fit onto the front of the heater that routed air into a 3" diameter insulated air hose (from McMaster-Carr) which then ran up over the driver axle and up to the front of the bus along the driver-side of the radiator. Just in front of the radiator, I connected it to the original air system. I took the original Vanagon rear-heater fan control and popped it into the dash. I was able to get reasonable heat, but rainy weather continued to be an instant-fog issue. And, the air source was less than a meter from the exhaust pipe, so, when we were sitting still at a traffic light, we would get a nice lung-full of diesel exhaust unless I remembered to turn off the fans when we were decelerating. Considering how it was with the air-cooled engine, this was still leaps ahead. From oily, semi-warm drifting air to warm diesel-exhaust moving with purpose, it was a definite improvement. Now, that the cooling issues have been solved, I can focus on restoring, or rather, improving this system.

That was a lot of context, and not hardly any content. I know. So, I'll spill my plan today, and then next time I'll start on the work. I am going to move the Vanagon rear heater from the auxiliary battery tray under the bus just in front of the radiator. I will route the air through a different custom register into the old air system. Coolant will be plumbed, electrical will be run and eventually a cable to control the coolant flow will be added. I hope. Maybe I'll figure out a way to source intake air so it's not all exhausty nor damp. Big plans. As always, I'm sure I'll have lots of errors and discoveries along the way. I'll do my best to document it as I go.

That's it for today. Thanks, as always for following along--