Saturday, November 27, 2010

Fanning the flames of progress

Sorry I haven't posted much in a while. Honestly, there hasn't been much to post about. I have a small update on the defrost efforts, and a new revelation about the inter cooler. Last, I took my son T up to Mt. Hood Meadows for a day of snowboarding - total Fall highlight.

Fan Fun
I have the rear heater unit in-place, the switch in-place and the wiring run. After spending a few hours trying to figure out which wire should be connected to which male plug on the heater unit, I found this thread on TheSamba ( With the picture, and some logic, it totally makes sense. I made the wiring corrections, but... the resistor doesn't work anymore. Fun stuff. I got the highly-maligned symptom of the fan only blowing on the "middle" setting, which, it turns out, means the resistor is bad. So, now comes the question: do I replace the resistor with a stock replacement, or go new-style? "what's this new-style," you ask. You install a true-rheostat concept like this. For the stock-lovers out there, I've already pissed you off with this whole project, but bear with me for a sec. The true-rheostat solution is $60 where the stock solution is around $35, assuming you can find it. I haven't had any luck finding a stock resistor, but I'll be leaving the fan in this on-off configuration for now. I have a defroster, and that's all that matters at this point.

Inter not-cooling
I am unable to place the stock inter cooler within the space I have after the heater is in. I'm looking for a Saab Blackstone inter cooler instead. Why? They take up a little less space, but are reportedly more efficient. Also, the inlet and outlet are both on the same end, improving the placement choices. Assuming I find one, and have it in-hand relatively soon, I'll cover that install. I know I will need more silicone tubing, so the install will take 2 delivery cycles - one for the inter cooler, and one for the tubes. net-net, I won't be test-driving over Christmas.

Snow good to see ya
Last Sunday, my some T and I drove up to Mt Hood Meadows for some snowboarding. I've gone sliding a couple of times, but I haven't really had good conditions before. Mt. Hood had received fresh snow the night before, and we had some flurries while we were there. The result? Groomed powder runs, and some great sliding. Our first ride on the lift was just after 9:AM, and after 7-8 runs, we called it a day around 2:30. I'll upload pictures later.

With the heater troubles and the ridiculous darkness this time of year, my motivation has slipped. Its been a couple months since I heard the engine run, and that doesn't help. I'm trying to re-motivate, and get the inter cooler resolved. Once that's in, I can test-start the engine again, focus on finishing out the little bits, and take a test drive. I won't feel close to finished again until I hear that engine run again. Sigh.

Sunday, November 21, 2010


Today, I got a couple of hours, so, with a steady rain and 35* work conditions, I decided to focus on something inside the bus rather than underneath it. I had a choice, either the fan control or the coolant flow valve control. I decided on the fans. I'll go into that today.

Wire Bundle
I had already bought the wire, so I figured I had all the parts for doing the fan controls. Using 14-gauge wire, I created a 3-wire cable bundle. I chose yellow-white-blue rather than the usual red/green/black combination, simply to be different. Like the wire bundle I ran for the ignition controls (link), I ran the cable through the large rear cabinet, along the outside of the low cabinet and stove/sink unit to the spare tire hole. I had drilled a small hole in the partition wall for the ignition cable, but I needed a new one for this new bundle. The wires then followed the same path along the edge of the door opening under the carpet to the A-pillar (next to the clutch pedal). The wires routed behind the fusebox and over the steering wheel support to the series of switches to the right of the ignition.

Switch a switch
My old 1972 dash controls were extremely simply by modern standards. To the right are 3 switches: dome light, wipers and hazard (left to right). The dome light switch doesn't actually do anything anymore. My dome is wired directly to the accessory battery fuse-block now, so this switch was useless. I chose to remove this switch and re-use the dash-hole for the fan control. After looking through both the Bentley and the Idiot's book, I was unable to find printed instructions for removing a switch. I went digging through my old parts and found a few old switches. By examining their construction, you can tell that the hand-knob just twists off (lefty-loosey). This leaves the stem and a round threaded silver collar sticking out of the switch body. The round silver collar also hand-twists off (lefty-loosey again), leaving a gray female collar attached to the switch body. By applying this learning, I was able to remove the dome light switch. If you have a switch that is correct for your model year, the install is the reverse of that removal. My fan switch, though, is from a Vanagon, so I had some more work to do.

Retrofitting a Switch
The Vanagon switch is much more modern. The switch housing clicks into the outer skin and the outer skin clicks into the dash. The outer skin of the fan housing does not integrate with an old bus, so I set it aside, leaving me with the switch body and the hand-knob. Unlike the older knobs, this one just slides into place and remains in place through friction. This may be useful later if I can figure out a way of re-using some of the outer skin. Anyway, to get the switch housing to hold in place like an old-style switch, you need to re-use the threaded silver collar. Since the new-style switch doesn't have anything to thread into, things get interesting. I went through my spare switches and found one that didn't work (tested with multi-meter) consistently. I cut the gray female collar off of the bad switch, filed off the rough edges and crazy-glued it to the Vanagon fan switch. I love how one sentence can summarize 30 minutes of effort and who-knows-how-much problem-solving time. With the gray collar firmly in place, I was able to wire up the switch and install it.

Wire Color Notes
As I mentioned above, I chose to use yellow / white / blue as my wire color choices for the fan controls. I'm sure a time will come when I'll have to diagnose a problem, so, for future reference, the yellow is for "low", the white is for "middle" and the blue is for "high". I striped and wired up connectors for the bundle. I tied them into the fan switch following the pattern I just mentioned. The switch still needed a power source, though so I located the B+ source for the original blower fan signal.

Once wired, the switch settled into the old dome light hole, and hand-tightened in. From the picture, it doesn't look straight-stock, but it does look pretty good. If I get all trailer-queen anal about it, I could probably find a hand-knob with a fan icon on it and figure out a way to get it to interface with the switch body. I just want it running and not have things looking half-assed or half-finished. This meets that bill. That's all I have for today. Over Thanksgiving, I'll get the heat box in, and I'll post on some changes / modifications I needed to do to get it run-ready.

top - view from the ground when I slide out from under the bus.
middle left - Vanagon switch modified with gray and silver collars.
middle right- 2 dome light switches, one after the gray collar was removed.
bottom - the fan switch installed next to the stock wiper control knob.

Sunday, November 14, 2010

heat placed, intercooler displaced

My time availability hasn't meaningfully improved since the last post. Somewhere I heard that the US is most productive (in GDP terms?) between Labor Day and Christmas. I can say that work has been distracting, but it wouldn't be fair to say that was the cause. Anyway, I have found a few hours here and there to get banging on the bus. I'll cover the highlights.

Heater Core Placed
After looking at putting the heater core inside the bus in a few locations, and trying to fit it under the floor of the cab, I have placed it in the alternate battery spot (under the spare wheel well). This location is already a little busy, with the intercooler and air filter as well as a bunch of wiring. So, this wasn't easy to get going. It still needs to be mounted. When I was working on the intercooler placement last Summer (or the Summer before..) I cut a section of tin out of the left side. To get the heater working in that space, I needed to cut the rest out of the way. The coolant lines will run from the left side of the engine, under the spare wheel well and along the body, curling back towards the right to the heater core. For a core, I'm using an old Vanagon rear-heater unit with a snorkel attached to it. The snorkel is still getting firmed up, but the mock-up worked well. Anyway, the snorkel will connect to a 4" diameter insulated flex-pipe that runs under the bus (over the axle) around the radiator to the original air line at the middle/front. Switching the fans and controlling the flow of coolant into the heater still needs to be devised.

Intercooler Displacement
Fitting the heater demonstrated that the intercooler was just in the wrong spot. As it was, getting in and out of the engine compartment on the left side was virtually impossible with it placed where it was. I found myself removing it frequently to do pretty much anything on the left side. Since the turbo an the intake are on the left side, the intercooler will stay on that side, but I'll be dropping it lower, down into the slipstream and rotating it flatter so access is much easier. Ultimately, it will operate much like the radiator does - with a puller fan placed underneath it.

Air Filter hassles
Another challenge on the left side is getting the air cleaner space to do its thing. I had something pulled together "well enough", but it wasn't game-ready. I'll need a 45* bend (another part to buy) to stitch into the set up, as the stock flex-tube is just too long to be effective. This became more obvious as the coolant lines and the flexi-hose for the heated air were introduced. Once the 45* bend arrives (still to be ordered), I'll be able to finish this off much more cleanly.

Exhaust Reroute
With the move of the heater into the engine compartment, and, more importantly, the insulated flexi-hose, the route of the exhaust has to move. The route from the turbo has been unchanged from stock, so it ran straight to the left out behind the rear tire. That was not ideal anyway, when we think about the "fresh" air we would want entering the heat system, or an open window when sitting at a red light. I was assuming I would need a custom run anyway, and now there's no question. The exhaust will route straight down, instead, and curve back to the rear along the bottom edge of the engine block. I will mock-up something so I can account for it while placing the intercooler. I don't want either the intercooler nor the engine to pick up heat from the exhaust as it passes. This will get interesting.

As you can see, things are getting more challenging, but I'm glad I'm finding these issues now rather than after a Summer of camping fun while winterizing. I'm going to focus on finishing the heat and the air filter completed first. Once they are done, I'll work on the exhaust and intercooler at the same time. I didn't mention that I did get the temperature sensor replaced, but with the different systems opened up, I can't test the engine. My plans for a holiday-season test flight may have to be pushed out. We'll see. Thanks for following along, and I'll post some pictures of this stuff when I'm on my other computer.