Electrical issue??

[Lrutts]

So i was driving my e30 today and as I turned into my neighbourhood the car just died out. So i tried to start her back up. Then smoke started poring out of my dash and i could smell electrical wire melting. So I stopped trying to start it. Looked under the hood and saw smoke coming from the fuse box, I opened the lid and some smoke came out but the wind took it away pretty quick.

I then looked under the dash and could still not see any evidence of where this smoke came from. I started to push her the 2 blocks I had left until I was home. After a block I decided to try to start her again. She started up, ran for a bit, then died. I waited longer, started her up, she made it home, and kept running no problem.

WHAT THE HECK HAPPENED!!?!?

[jlevie]

Something shorted. Since smoke came out from under the dash and from the fuse box I'd hazard a guess that all of the car's body wiring will have to be rplaced.

[Lrutts]

odd, wouldn't it have just stopped working for good if thats the case? By all the body wiring do you mean the wire harness itself?

[glucklich21]

First things first, take apart the fuse box and see where the short occurred. Then trace it back to the dash. It's best to remove it for this part. At that point there's a few a few harnesses right at the firewall on the interior side. Cruse, 13 button (if equipped), SRS (if a 90+), radio, antenna, and the dash harness <--- Yes it's separate. Take a good look and see if you can find the fault. Obviously the ones I listed are easily replaced if they are the source. However if the problem lies with the body harness, you can try tracing it back farther to see what caused the problem. Patch it up and see if the problem is solved. The electronic troubleshooting manual is going to be your friend when you're messing with the electrics.

We honestly can't be any help till you figure out what shorted first. ;)

[billybobjoseph]

glucklich is right. While you're at it check your main and fuel pump relays, they can have intermittent failures.

[billybobjoseph]

What jlevie means is that shorts can occur in an old harnes where the insulation off the wires have become brittle and fallen off. The place where this usually happens is at a point where part of the harness bends - going through the firewall for example. The short will happen between two wires that have lost insulation and an arc occurs through them. When trouble shooting something like this you will be looking at blown fuses and using an ohm meter to check circuits. The problem is you may not find the short if it's intermittent. You could replace all the wiring for a circuit where a fuse blew but what about the other wire thats lost insulation. Also, if one or two of the wires have lost insulation more probably have as well, or will soon. The best fix is to replace the harness.

[Lrutts]

I found the wire a few days ago, its green! haha. It goes through the firewall down to where my knees are, its all melted and shitty looking. Whats odd is the car runs just fine now. My brother is a BMW tech, so i am just going to wait till he is back from vacation, his specialty is electrical work, so it should be pretty easy for him :)

Thank you guys, what is this electronic trouble shooting manual thing?

[glucklich21]

Um green? Is it a bigger gauge than the rest of the wires? If so, that ain't good. That green wire provides power for quite a few things, the ECU being one of them. Do not drive it in this condition, you're setting yourself up for a shit storm that could result in a fire.

[billybobjoseph]

If its a very small guage green wire it may be the one that comes from your starter and goes to the abs light in your dash and the abs relay under your dash. Did you put a new starter in recently?

[Kershaw]

im betting its the power wire to the window switch.

[jlevie]

That green wire sounds like it might be the "Hot in Run and Start" lead from the ignition switch.

[Lrutts]

Sorry about the not so good pictures, they are off my phone. So as you can see, its that odd wire that is in a bit of a loop by the top of the clutch pedal on the left side of it. It looks brown now, but when i look close, i can tell it used to be green.

[billybobjoseph]

can you follow it to see a place where the original color and tracer are apparent?

[Lrutts]

I have tried, but everything is to tight. Can I just cut the black tape (almost like hockey tape) to loosen it all up?

[billybobjoseph]

yes you can, easy to replace later. Another option is to disconnect your battery ground and then power lead, and cut the wire. You aren't gonna want to leave that in there anyway. If it goes to the engine compartment ( make sure first ) have a friend go to the engine compartment while you push the wire so he/she can identify which one it is and pull it through, then just follow by hand to where it goes. You'll also have to follow the other end to where it goes.