Wednesday, July 25, 2007

1975 Color Wiring Diagram

Since I'm on vacation, 750 miles away from my car, I spent today colorizing my scans of the Haynes 1975 current flow diagram. I'm glad I did -it turns out it is different than the 1974 (especially the headlight wiring). I could never find color 1975 diagrams on the web anywhere, so these are presented under copyright "fair use" terms - the originals are still copyright by Haynes, of course. The images are somewhat useless without the original manual, since I did not upload the page with the key.

I may replace these with further cleaned-up PDFs some day. But I'm not in a hurry :-)

Edit: After McMark at kindly stitched these together, I found a bug in pages 3 and 4. So, these are the new pages 3 and 4.

Saturday, July 21, 2007

Interior trim, phase I

Before I can do final gauge/interior wiring, I want to get the interior put somewhat back together. So, here is the dash, dry-fitted (not bolted in yet):The AC kit has 3 new gauges to install: a 144V voltmeter, a 12V voltmeter, and an ammeter. The instructions want you to kludge them on to a 3-gauge accessory gauge panel. However, Auto Atlanta has a prefab aluminum gauge surround that will work perfectly. Here are all but the speedo dry-fitted:
I'm going to install an electronic speedo (3 3/8 inch) in the hole in the right (I had an electronic speedo planned from the beginning - I hate the idea of cables spinning inside my cabin). There are plenty of holes in the surround for various indicator lights that are no longer present since the gas gauge and original speedo are gone (generator, battery, high beams, etc.)

I also did some more work on the rollbar. I installed the rear window, and the pad (the original pad is in pretty bad shape. I'm debating if I care enough to pay $345 to have it recovered).
After I got this picture on the computer, I said, "Huh! What's that yellow blotch in the lower left corner? It's not on the car..." Zooming in reveals:
...a hornet! During this whole car saga, there has been a parallel saga of my battle with the hornets (for one thing, they seem to be attracted to the whine of electric power tools, as well as the various chemical smells of stripper and paint). A "fun" momento of that battle...

Rollbar Trim Repair

Taking a break from electrical work, I attacked the rollbar trim. The PO had done a fairly poor rattle-can black paintjob on it (he did not even remove the original chrome!) Here is halfway through the sanding process:After sanding some more, I discovered more bondo - the PO really loved bondo - on the right trim piece:
After attacking it with a heat gun and more sanding, this is what was revealed. Structural bondo, gotta love it:

I debated painting it in chrome or redoing the black. Ultimately, I chose black. I redid the main rollbar trim piece as well. Here it is, all put together:

Only You Can Prevent Porsche Fires

I've been remiss in blogging, but have done some more work. If you recall, when I was last discussing the wiring harness, I mentioned that I had a smoker. Turns out that the green/black headlight motor wire had contacted the body, resulting in a direct (unfused!) 12V connection which, left a few minutes, started a minor fire. I stripped the wire in question from the harness (inspecting the remaining wires to make sure they were not damaged). Here is what I found:Further evidence that smoking (wires) can be hazardous to your health:
In related news, I briefly had my turn signals working. However, after plugging in my gauges, the turn signal fuse started blowing when I turned the key. After debugging through it, and with the use of my handy-dandy multimeter, I was able to isolate it to this wire to the tach (which I thought had been attached here - obviously incorrect):

Unplugging this wire removed the turn signal fuse short. The reason it shorted is that the turn signal light is grounded to the tach, and the wire in my hand is 12V hot-when-ignition-is-on. And therefore 12V went directly through the turn signals, causing the fuse to pop.

Monday, July 16, 2007

144V pack is charging

Following TimK's lead (here) I hooked my batteries up to the charger. This involved:
  • Installing a NEMA 6-20P plug on the end of the charger cord to match my 240V extension cord I had previously built
  • Building custom 12-gauge interconnects with a crimper and round lug ends
  • Hanging the charger in the preferred vertical orientation
  • Wiring it all up and plugging it in.

And here is the completed contraption. The 1/4 inch plywood at the left is ready to be placed on top of the batteries to prevent things from falling onto the terminals and shorting them out (look at all those paint cans just waiting to fall :-)

Wiring Harness

I got a few things done this weekend. First, I rebuilt the main wiring harness. This involved:
  • Stripping the old electrical tape off (not too hard - it fell apart)
  • Cutting out the seat belt detection circuitry (a pain in the rear to thread thru the tunnel) and rewiring it to be unnecessary
  • Putting Flexguard and new electrical tape on
  • Installing a JWest fuse panel upgrade

Here it is all shiny and new again - and a whole lot less than $2500 or so for a real new one.

Next, I installed the harness from the dash back, then forward. This requires some careful fiddling to make sure you don't tie a knot in the harness as you thread. But I got it installed.View of the harness in the engine compartment

And here's the rat's nest where the dash will be. The blue tape has labels for just about everything.

Today, I even hooked up a 12V battery to the mess and started testing connections. The hazard/turn signals were pretty easy. The lights are harder - I even smoked a wire! Be careful of those high-amp circuits... why the breaker did not go is a topic for another investigation. I think the wire smoked because the bare end short-circuited against the chassis. The wire in question is one of the headlight motor wires - fortunately, easily accessible (I stripped the shrink-wrap off that portion of the cable and will replace the entire wire in question).

Sunday, July 8, 2007

Motor Installed!

View from inside the cabin, through the rear window
View from under the car, driver's rear.

I took the opportunity to replace the transmission mounts with new mounts from Pelican Parts. I also installed new engine mounts (the rubber things on top of the engine bar) and engine bar bolts.

I did have a little trouble getting the engine bar aligned. What I finally figured out was to support the motor with a 2x4 so no weight is on the bar. With the motor supported, you can loosen the bolts mounting the plate to the motor, and adjust its position.

And, I used the Pelican Parts "lower the car onto the engine" technique again, just as I did for the original engine drop. Seems much safer to me than raising the whole powertrain up on a transmission jack.

Controller Mount

I got the controller mount installed today, so my rear trunk no longer has a giant hole in it (it has smaller holes, still, but that's another story). It definitely takes two people to torque down the bolts; thanks to my wife, Jill, for her assistance!

Friday, July 6, 2007

Back From Paint!

And a nice paint job it is, too. Now, to reassemble it...

Thursday, July 5, 2007


The batteries showed up today. I'll store them in the battery boxes to reduce the risk of acid leakage while I work on the car (also, so I can put the tops on to prevent people from accidentally dropping metal objects in and shorting them out!). The little black battery is my 12V accessory battery, that I purchased locally.

Following the recommendation of Electro Automotive, I ordered from Jim Ramos at American Battery. Their service was excellent, and the batteries are exactly as requested. Their address:

Jim Ramos
American Battery
3488 Arden Road
Hayward, CA 94545
Phone 510-259-1150
Fax 510-259-1160

Tuesday, July 3, 2007

Motor + Transmission

The second task I undertook today was to mate the motor to the transmission. First, I securely clamped the motor to my workbench (makes torquing the clutch bolts to 80 ft-lbs much easier!)
After much trial and error, I got the flywheel securely mounted at the proper distance from the mounting plate (first try was too far out; second try was too far in; third try was just right). You can see the felt washer peeking out from inside the crush ring - it gets really crushed...
Clutch pilot tool inserted and clutch mounted
Pressure plate mounted and secured. After this, you remove the pilot tool.
I also rebuilt the throwout bearing assembly. Not pictured, I replaced the throwout clips, the ball socket, cleaned everything thoroughly, and then reassembled (appropriately greased, of course!)
I then put both transmission and motor on rolling dollys. First try: engine was way too low:

So, I shimmed the motor up. It *almost* matched, but you could tell something was not aligned internally. I peeked in through the little "windows" (and shined a flashlight in through th starter motor hole) and this is what I saw: the pilot bearing was just a little low, but low enough that it did not mesh. So, more shimming ahead:After getting it all aligned, here it is (no bolts attached yet):And the final bolts in place (the three bolts that don't go thru the starter blockoff are about 16mm too long - they are 100mm and standard parts are 84mm. 100mm is all I could find at the local HW store - I lost my originals somewhere... I may cut off the excess length of these before I mount it in the car. I also transferred it to a single dolly, in anticipation of getting the car back and mounting the assembly inside the car.
So, summary:

  • Make sure you have the motor firmly clamped
  • If you're rebuilding your throwout bearing, use a Dremel-type device to carefully shave away the ball joint bearing surface.
  • Have two furniture dollys and lots of spare scrap lumber (for shims) for the final assembly
  • You can look in through the little trapezoidal "windows" as you assemble to check for alignment of the main transmission shaft and the bearing
  • Don't lose your original bolts. Ahem.

Motor Washer Upgrade

Today was a busy day. First, I decided to upgrade the washers on my motor with the new ones that Solectria kindly supplied. Here is a picture of the old washer (the teflon-looking deformed thing surrounding the bolt).
Here is the washer, removed. Solectria says that these can fail, leading to bolt loosening and motor failure.
These are the new washers - tradtional flat and split ring washers. Nothing special.
Torquing it down. Note that there is an error in Solectria's documentation. It says to tighten the bolds to N-m or 50 foot-pounds. One or the other is off by a factor of 10, since there are roughly 1.36 N-m per ft-lb. I am certain they meant 5 foot-pounds since the bolts did not seem to want to go about about 25 foot-pounds. I set mine for 5, like this: