E34 Electric Issue: When cold, windows & locks don't work.

[mazdaf]

When i turn on the car in the morning, and it is cold, the windows and locks don't work. The winshield wipers don't work on speed 1 & 2. Yet, the radio, power seats, heated seats do work.

My first thought was the fusible link, but it was fine, i replaced it anyway.

So what's next?

If it is 40F+ outside, it takes 5 minutes with the car turned on, for the windows and doors to start working. This morning it was 25F outside, and it took a good 30 min with the car on for the windows and locks to begin working.

Any ideas?

[Torque]

Sounds like a bad general module to me. It controls that stuff; very possible that a bad solder joint is making itself apparent with the cold.

It's under the rear seat, on the left side, under a plastic cover ... it's a green (or black .. depends on year) plastic box about 8x3 inches in size, says GM on it. Try to borrow one from someone and test to see if that's it.

The bad news is: they can't really be repaired ... it's a maze of solder and chips, but the good news is they are fairly cheap used.

[mazdaf]

There is a GM and a RM module under the back seats, they look like VHS tapes, and can be pulled right out (they are actually under the back seat with a plastic cover that needs to be taken off, next to the fuses). I'm probably 1 week away from spending money and replacing these. In the meantime, i used a multimeter and this is what i found.
Battery when the car was off - 12.14 V
Battery red to car ground - 12.14 V
Fusible Link - 12.14 V
Under the hood fuses - 12.14 V
Under the hood Locking system fuse # 24 - 11.90 V
Under the back seat fuses, which includes power windows - 11.90 V

I'll let the car warm up and when the power windows and locks work, will test the fuse V again to see if they are up to 12.14 V, if so, my conclusion would be, if the power reaching the locks and windows is less than 12.14 V then i will experience the problem. This is a theory that has not yet been proven.

[mazdaf]

I've seem to have found another person with the same exact issue where the windows, locks, wipers and sunroof don't work, but radio and header blower does. Here is the link
Bimmerforums - The Ultimate BMW Forum - View Single Post - Power windows and sunroof not working

Also i found a awesome site for wiring diagrams for the E34.
BMW Wiring Diagrams

[rollis]

I'm having very similar problems that just about tonight. I have no power to my radio, wipers, power seats, door locks, and sun roof. Over the past week I've noticed my radio would cut-off and back on again but wasn't aware that it might have a combo of all these until it cut off power for good.

[mazdaf]

Originally Posted by rollis

I'm having very similar problems that just about tonight. I have no power to my radio, wipers, power seats, door locks, and sun roof. Over the past week I've noticed my radio would cut-off and back on again but wasn't aware that it might have a combo of all these until it cut off power for good.

Your issue is most likely with your fusible Link. It is different from mine because my power seats, and radio continue to work. Follow this link for a solution. If i'm right, your solution is simple and inexpensive.

http://www.bmwe34.net/E34main/Mainte...sible_link.htm

[rollis]

Originally Posted by mazdaf

Your issue is most likely with your fusible Link. It is different from mine because my power seats, and radio continue to work. Follow this link for a solution. If i'm right, your solution is simple and inexpensive.

BMW E34 Website

You are correct. I went out earlier and confimed I had a break in my fusible link. Mine is under my rear seat (89 535i) and is not un-boltable like some. BMW Dealership said it runs over $200 for the kit. I'm prob gonna run down to my local car stereo place, they have said the can fix me up for $10.00 with an 80 amp link

[mazdaf]

Originally Posted by rollis

You are correct. I went out earlier and confimed I had a break in my fusible link. Mine is under my rear seat (89 535i) and is not un-boltable like some. BMW Dealership said it runs over $200 for the kit. I'm prob gonna run down to my local car stereo place, they have said the can fix me up for $10.00 with an 80 amp link

I purchased my fusible link online for $1 for a package of 2 plus $9 for shipping. It 5 days to come and 5 minutes to fix. Glad you found the problem.