1985, T16, w/auto Project (fresh aquisition).

[Flatfronter]

Just found a low millage, (95k) 1985 t16 w/auto.
My goal has been get my gf into a C900 (hence the auto) and this resent find is the perfect candidate. The car was advertised as having electrical issues and from what I've seen so far, it seems isolated to the radiator cooling fans, the drivers power window and the heater (not working) Everything else works pretty well, e.g. Drivers window, sunroof, mirrors, lights etc.
In the photo you'll see bare wires. It looks like a shorting event may have happened at some point. The car turns over fine, but wont start... still not sure if I have fuel or spark.
I have plenty of manuals on hand and an 8v, 900S donor car with power options from the same year.

I want to take a methodical since time is not an issue, but I'm weak in the electrical dept and will need some help. This is the first t16 I've wrenched on in about 10 years so I'm reading up on the t16 ignition this morning. More photos coming. Wish me luck!

[Crazyswede]

the 85's were prone to wiring harness insulation failure. It was an experiment to try a different type of wiring apparently...it worked great for a while but did not age well. You will be finding bad connections for some time to come. Its best to disturb it as little as possible and keep a fire extinguisher in the car, or plan on doing some sort of harness swap in the future

[DrewP]

Nice find! The connectors in the driver's door jam of both my '85's look the same as yours. I just have the wires pulled far enough away from each other that they don't interact too much.

Really easy way to check condition on the fuel pump, injector pulse, and ignition pulse is to get a spare distributor and plug the hall sensor connector in and turn the distributor shaft by hand with the ignition on. You will hear the fuel run thru the rail, hear the injectors click, and can easily ground a spare spark plug on a wire to the intake manifold or wherever and verify you have spark.

The running systems for the LH 2.2 cars is very straightforward.

[johnshan]

Nice black 85. my wiring also looked just like that. I took some liquid wire tape to it and it has held up ok. I would check your hall effect sensor connector on the distributor. The connector is poorly designed, and will result in a no start condition (guess how I know that). A quick check is to have someone crank the engine over while giving the plug a jiggle. good luck with the 85 wiring woes, they'll get worked out slowly but surely.

[Flatfronter]

UPDATE: The car has spark and suspect -fuel problem.
The toasted harness in the photo runs towards the rail... looks like it may service the FI system.
I bought a volt meter, but I'm so bad with electrical jargon, it's like holding a tampon in my hand and I don't know WTF to do with it.
The other side of the harness in mention has good healthy wires. Found a good use for that liquid tape shit under the fuse box, but I'm not spending $10 on it. I'll just use some leftover gasket sealer... duh!

[Geoff]

Did you check the fuses? I sold one of my '85s and a few months later it quit on the new owner. They had it towed to a garage and the garage told them that the exhaust heat shield must have rotted away, causing the floor to rot away and the wiring harness to melt and blow out the ECU. This was all untrue because I had replaced the heat shield. I had them tow the car to my house and had it running within 5 minutes. Fuse had blown for no apparent reason.

The bastardized cooling fans might be due to the relay. The relay typically goes bad and the fix (I think it comes from a technical service bulletin) is to remove the relay, cut the two large wires away from the relay holder, twist, solder, and shrink wrap them together. The relay is mounted to the inner fender on the driver's side, near the air snorkel.

[Flatfronter]

fuses and relays all check OK

[Jordan]

I can't tell which connector that is, but one of the two supplies the 12v power from the fuel pump relay back to the pump.

[jskrebs]

Its a bitch, but best to pull the entire harness out of the car and fix everything at the same time. I also added T5 but that's optional.

[Flatfronter]

I was just about to jump the FP relay (between 30 and 87) for some testing when I discovered there are only two connections present in block G. The arrows correspond to the two locations. One wire is black wire and the other is a blue tied to a white-yellow. All my other 900s have block G fully populated. The only variable I can think that is different is this car is an auto and not a 5 speed. Other than that, I'm without an explanation.

[gmreider]

The 85 turbo 16 V has the main relay and the Fuel pump relay hidden with the ECU under the kick panel carpet on the right side (passenger).
to make the fuel pump run jump from the top of fuse 28 to the top of fuse 30( fuel pump). when I say top of fuse , if you look at the fuses you can touch a wire right at the top of the fuse without removing it. I think fuse 28 is hot all the time and by jumping you apply current to the fuel pump (fuse 30) bypassing the relay. Hope that helps you.

[Flatfronter]

As I reported, the car had spark, but I later determined it insufficient. The source later became clear, a torn and battered Hall sensor that is quite evidently a horrible design flaw. I've tried to source the part but to no avail. I pulled the rotor shaft from my 85 8V parts donor only to discover the parts aren't compatible. I was able to splice the 3 tiny wires but have concerns over fitting it all back together under the plastic wire shield and wished I had a solder gun.

[Jordan]

Best bet would be to swap over the later ignition components or I'm pretty sure I have an '85 distributor you can have.

[Geoff]

That same issue caused me tons of problems on my '85 SPG. The plug came loose off the distributor and the wiring got cut by the trigger wheel for the hall sensor. I soldered it back together and somehow got it back in but it didn't run all to well. Then it started retarding the timing so it would only run under heavy boost. Then I had to get it towed home. I swapped to a later distributor and a full section of wiring harness including both plugs for the hall sensor and ignition amplifier.

[Flatfronter]

thanks to Geoff Jordan. For now, I just want to get spark back so I can troubleshoot the no start/ no fuel condition. I hope to see you both at the eEuro swap on the 27th.