Attention: ALL E36 owners beware - WIRING PROBLEM

[BiMmEr JoN]

I took pictures of all the wires and the burn marks. I'll try and post them tonite.

[GundamWZero]

Well, all I want to do is to convert mines to US specs. I am trying to find out what I need to get to make the conversion. I have a 320i and I want to bring the car back to the States from Germany.

[themadhatter]

um...wrong thread?

-Ron

[Boomer]

^^^ hahahah

Speaking of electrical problems....

On my 93 325is, when i lock it, sometimes the passenger door doesnt lock and sometimes it does. I also have the original BMW alarm with the remote and everything and same thing happens when i use the alarm remote. It also works when it wants too, one day it does and one day it doesnt!
i think my car has a brain of its own and its very cranky!

is this sttuff any serious and something to look into or just leave it as it is untill i get some $$$ ?

thank you


Renat

[Furious]

wow thanks for the heads up. im gonna check them out sometime this week. i wanna see these pics.

[DoreenNZiv]

what ever happened to those pics? i think i may be having the same problem(s) w/ my car... my left side lights are not working.

[G. P. Burdell]

Your local BMW dealer sells a replacement wiring harness kit for the trunk lid. The part number for a 1997 328i is 61 12 8 391 788, and the list price is $78. It is a special order item.

In addition to the wiring harness and rubber covering, the kit includes several short lengths of clear shrink tubing and little crimp-type connectors to hook up to your existing wiring inside the trunk.

I strongly encourage you to verify that this is the correct part before you order it. There is a different part number for the 325i. Remember that electrical and special-order items are generally non-refundable.

I just picked up this kit from the dealer this morning and hope to install it this weekend. Although there will be more work involved in fishing the new harness through the trunk lid and connecting the new wires to the old, it seems a better long-term alternative to cutting the waterproof rubber covering and attempting to repair already-damaged insulation.

[G. P. Burdell]

My husband and I replaced the original wiring harness today with the replacement I described in my previous post. I'm glad I caught this one early! Read on...

All of the wire colors match up. The new harness and its connectors can be fished through the trunk lid easily, as long as you attach a string to one of the old license plate light connectors before you pull the old harness out completely. Then tie the string to the new harness and pull it through.

At a minimum, you will have to plug the new harness into:

--Left and right license plate lights (one connector each)
--Trunk light switch (the black plunger to the left of the latch)
--Trunk lock actuator (two connectors)

You may also have to plug the new harness into your rear spoiler if it is wired for an integral third brake light.

There will probably be extra wires (the new harness had 17 wires, the old harness only 10) leading to as many as three unused connectors. This means you will have to find out which wires to splice into the existing wiring in the trunk. A little deductive reasoning, a circuit tester, and the Bentley manual electrical diagrams will help you figure everything out. It's not too difficult. Label everything carefully and check twice before you splice or cut anything.

Here's the scary part. After removing the old harness, I pulled the rubber covering off and looked at the old wires. Attached is a picture of the ugly sight. Out of the 10 wires in the harness, five of them were missing their insulation and fraying.

The large blue/gray wire and the white wire were the most damaged. They're two of the five wires that go to the trunk lock actuator. These frayed wires caused a short that blew one of my central locking fuses (No. 35) and left the whole system inoperative. The fraying on the brown/white wire that goes to the trunk light switch also explains why the trunk light would occasionally go out for no apparent reason. Note the scorching on one of the ground (brown) wires.

The insulation appears to have gone first, then the wires. This is probably due to repeated exposure to heat over time. The heat dries out the insulation, which then cracks when the wire harness flexes.

If you have not looked at your trunk lid wiring, DO IT NOW.

Even if you have one of the last E36s made, your car is still susceptible to this kind of wiring damage!

[G. P. Burdell]

Here's the picture.

[G. P. Burdell]

The green arrow in the attached picture shows where I found the cracked insulation and the fraying wires.

[Twisty]

Holy Moly! I need to check now... thank god I read this now that I got my 325i!!!

[ruffneck119]

Thanks you all! I have maybe the same problem all my interior lights seem to flicker a bit. I will check this out ASAP!!!

[Boomer]

mine(325is 85,xxx miles) doesnt do anything nor shows any sign... should i still check or i shouldnt mess around with the wiring if nothing is wrong with it?

[G. P. Burdell]

Originally posted by Boomer
mine(325is 85,xxx miles) doesnt do anything nor shows any sign... should i still check or i shouldnt mess around with the wiring if nothing is wrong with it?

Exposure to repeated heating and cooling (hot weather, direct sunlight, cold weather, etc.) causes the wire insulation to lose its flexibility. This process is accelerated if you leave the car parked outdoors.

I had intended to look at my car's wiring harness months ago, but the recent central locking failure forced me to do so.

I suggest you inspect your wires. Consider it preventive maintenance.

[Eurofied]

same kind of thing just happened to me, except with my tail lights. lost all my brakelights rear driving lights, turnsignals, and reverse lights. i had to go through and re-wrap every wire. blew a lot of fuses trying to fix that problem...

[Hyperion]

I just cut mine open.

There was one wire that the casing had cracked open, and one of the individual strands from the wire had broken.

[Dalowa]

Yes I asked my dad about this problem ( he was working for german auto service 16yr) and he sad that if the wires crack open and wires start shorting out they heat up and start malting the plastick away. So the soner you catch it the beter.

I dont have BMW jet but thanks to this poste ,that is gonna be one of the first things I'll be checking when buing.

[bajan boi]

Originally posted by dvx_movies
Yeah I think a pic would be nice as Quest330is said, because I am not sure which cover to strip? I inculded a pic with two arrows pointing to two sets of wires, arrow #2 point to the strip underneath the trunk cover, where u see your spare tire.


I hope I was close enough

Happened to me last winter - wires @ point #1 frayed and my doors would not latch/close. My man Des helped me out

[BiMmEr JoN]

Anybody have any luck with this replacement kit from BMW. I want to know how hard it is to put on. I know that there are alot of wires, is there a connector at each end of the wires that just plugs in. Anybody?

[AceHazardX]

It's a pretty simple DIY. Soldering would be the best fix, just go buy an iron and wire and you're good to go. Just match the wires back color to color.

Fabian

[G. P. Burdell]

Originally posted by BiMmEr JoN
Anybody have any luck with this replacement kit from BMW. I want to know how hard it is to put on. I know that there are alot of wires, is there a connector at each end of the wires that just plugs in. Anybody?

It is not difficult. You can do it in an afternoon.

On one end of the replacement wiring harness are the various connectors that hook up to your license plate lights, trunk lock actuator, trunk light switch, etc. On the other end of the harness is a bundle of plain wire. This end terminates inside the trunk, behind the trim on the left side.

The basic procedure is this:

0. Get the anti-theft code for your radio.
1. Disconnect the battery.
2. Remove the tool kit from the trunk lid. The 1/4" plastic caps below each hinge of the kit hide the screws that hold it in place.
3. Remove the expansion rivets holding the trunk lid trim panel in place. You can get new ones from the dealer, so don't be afraid to break them.
4. Remove the left side floor plate in the trunk (it's held in by two 10mm plastic nuts) and the left side tail light cover, then peel the left trunk liner back to expose the wiring. Remove the liner or tie it back with a bungee cord to keep it out of your way.
5. Unscrew the license plate light trim piece (held in by four Philips head screws), pop out the license plate lights, and unplug their connectors. Tie one end of a long string to the right side license plate light wire. This is the string you will use to fish the new harness through the trunk lid.
6. Unscrew the trunk light switch (the black plunger to the left of the trunk latch) from the trunk lid and unplug its connector.
7. Unplug connectors from trunk lock actuator and any other accessories (e.g., power for the third brake light in your rear wing).
8. Pull the old harness out of the trunk lid. Untie the string from the old harness after all connectors have passed through.
9. Locate the old harness wires in the trunk and cut them. Leave yourself a sufficent length of old wire. Pull the old harness out and discard it.
10. Tie the string to a license plate light connector on the new harness and fish it through the trunk lid. Plug the new connectors into the various accessories.
11. Insert the other end of the harness into the trunk and splice the ends to the existing wiring. Colors and wire gauges should match up. You will have to make at least 10 splices. If there are more wires in the new harness than in the old one, a circuit tester and the Bentley manual wiring diagrams will help you to identify unused wires. Tie these unused wires back. Use loom, tape, or zip ties to keep things neat.
12. Reconnect the battery and test all trunk lid accessories before buttoning everything up. Make sure the new rubber seals that came with the harness are properly seated in the trunk lid and the body of the car. Reprogram the date/time into the OBC and unlock the radio with your code.

As I mentioned in my previous posts, the harness kit comes with connectors and heat shrink. You may wish to substitute these items with your own preferred splicing method (e.g., soldering, butt connectors, etc.).

And as always, if you follow the procedure I have just outlined, you do so at your own risk. I am not responsible if you screw anything up or injure yourself or others.

Post here if you have any questions.

[TooTall424]

will check my wires tonight...

[BRUNO]

my window switches just went out and i checked the fuses and they were fine. I can't get my windows to go up. Does the trunk have the wiring for it. I just left my car at bmw dealer i hope it's not alot.

[G. P. Burdell]

There is no window-related wiring inside the harness leading to the trunk lid. The harness provides power for your license plate lights, trunk lock actuator, and connections for the trunk light switch.

If all of your fuses are fine, then it could be your comfort relay.

[AceHazardX]

I've had that relay blow out on me as well. Good luck on replacing it, not too much work.

Before you change the relay try that window kill switch on the right (right behind the steering wheel)

Fabian