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--