E36 Tail Light Failure Issue

[philgroshens]

Okay, let me start this thread off by saying I know there is a MASSIVE thread about this issue with E36 trunk wiring, however I've tried everything I can think of and I figure at this point I'm better off asking the masses than spending the next 4 hours buried in wiring.

My '92 E36 325i randomly decided to give me the "Tail Light Failure" message on the OBC last night (very strange, I drove it to the gas station and it was fine, when I started it to leave the gas station I got the error and it hasn't gone away since).

Along with this error, my passenger side tail lights do not work. The brake lights work, the signal lights work, and the reverse light works, it's just the marker lights that are non operational.

I have a spare tail for the car, so I tried swapping the bulbs into the spare tail and hooking up the wiring connector... no go.

Along with the spare tail, I have spare bulbs, so I tried those as well... no go.

I checked the fuses ... nothing wrong there.

After checking Bimmerforums, I found that the wiring harness that runs along the drivers side into the trunk has issues with fraying, as seen in the picture above. I spent about 2 hours cutting and re-attaching wires with electrical tape, and thought I had the problem all but fixed... however after re-connecting every wire in the above harness, my passenger side tail lights are still not working.

After looking at the wires as the leave the passenger side tail, and the wires that come through the above pictured trunk harness, I've come to the conclusion (and I could be wrong?) that the pinched trunk harness does NOT control the passenger side tail, and the wiring harness that goes under the black plastic trunk lip is the harness that feeds the passenger tail.

So, after futzing with wiring and tails all day long, I am still without passenger side rear running lights.

Has anyone else has this specific kind of issue, and if so what did you do to troubleshoot/remedy the issue?

[E36Lindberg]

If I were you I would tape each of those wires up individually with black electrical tape. Also check your actual head light switch and see if it rattles when you shake it. If you hear a noise there are broken pieces inside the switch so you would have to replace it. My passenger side tail light went out on me before.


This is a good site with diagrams on your cars systems

http://www.realoem.com/bmw/partgrp.d...84&hg=61&fg=95

[philgroshens]

I already doctored up the frayed wires with electrical tape, the issue persists though

[E36Lindberg]

new headlight switch!

[VmaxFlyR]

I seem to have isolated it down to the connection between the bulb holder and the rear light console frame which carries the actual connection from the harness. Check to see that the connectors on both are clean and tightly making contact.

Just wiggling the bulb connector seems to usually do the trick, though I know this is not a long term fix, it is working for now. Good luck.

[philgroshens]

I've tried brushing the connectors on the bulbs and the connectors on the tail with a wire brush to check for corrosion, no dice.

I have a spare headlight switch somewhere, I'll try replacing it and see what happens....

Wish me luck!

[E36Lindberg]

k I hope it fixes ur problem, reply back let us know!

[philgroshens]

Headlight switch was the culprit!!!!

I knew right away when I removed it, it sounds like there's many small pieces shaking around inside.

Luckily I had a spare headlight switch

Thanks to everyone who helped out!!! Much appreciated.

[E36Lindberg]

Told you!!!! Good now you won't get pulled by the pigs

[iski123]

Had both rear running lights go out at the same time..... is it likely this is also a switch issue? I've got to do a long night time drive in a couple days and can't wait to get in a new switch or any other parts.
I noticed the license plate lights are functioning fine, thinking it might be easy to just run off those to get me through till I can actually futz around and figure out the cause. I'll be digging into it tomorrow afternoon to start ruling out what was suggested above.