E34 window relay problem

[Steelbasher]

Hey all,

I've recently bought an e34 520i for myself. I haven't had any problems with it until just today where I noticed my battery was flat.

I can hear a relay clicking rapidly and inconsistently underneath the back seat. When I remove one of the fuses for the window lift I can hear the relay go absolutely mental. I have ordered the workshop manual but It won't likely arrive for a long while. I'm wondering if any of you out there have also encountered this problem or have any idea what is happening. I haven't had any experience with cars which rely highly upon relayed electrical circuits before!

Also upon locking the car I could hear the door locks trying to continuously lock themselves even after they were locked. I'm not sure if this is related though.

[The Night Rider]

I also have a 1995 520i, I am also from NZ, more importantly I also had the same problem as you (I had to go outside to check my E34 hadn't been stolen ha).

When I came back from overseas some time ago my E34 had a flat battery, and when I tried to start the car all the relays were going crazy, even the ones in engine compartment. It would run fine after jump starting but wouldn't be able to start itself after no matter how much charging, in the end I found the battery was basically too old and dead. After replacing it I have never had the same issue.

So my suggestion is even if the battery seems fine after charging, it would be good to get it checked.

Hope its as simple as that for you.

[Steelbasher]

Thanks The Night Rider,

I don't think it is the batter as it looks fairly good, I guess its hard to tell without checking it out properly. The guy I bought it off told me one of the windows wasn't operating correctly so I'm thinking this might be the problem somewhere. I just don't know if it would be the relays themselves or something to do with the connections somewhere along the line to the regulator.

[The Night Rider]

I don't know much about the E34 electrical system so I cant say much about it, however, if the relays are clicking it probably means they are switching/working correctly (this is just my understanding I may be wrong).
My battery also looked to be in good condition but was completely dead, if its easy for you to get checked I would still recommend it. Sometimes they have a glass indicator on top with a liquid inside to tell you the condition.

You might be completely right that battery is good but I just wanted to share my experience.

[Steelbasher]

I did see the glass indicator was black which I just assumed meant it had no charge. I'll take it down the road tomorrow and get it checked out.

[shogun]

Very easy, continued clicking basically means something is wrong. Pull the rear seat and check out which relay is clicking and hot.
Show us the location in the fuse box and tell us what is mentioned on the relay.
From E32 it is known that often the wiper pressure relay under the rear seat is making that problem, when the wiper pressure plastic gear is broken and they relay still tries to pulll the wiper down. That would be a black relay and there would be ADM written on the housing, that is German for Anpress Druck Motor = wiper pressure motor.
Here are the wiring diagrams by built year, these are US spec., so it might be a bit different on your EURO (or maybe import from Japan) E34
Based on production year: from around page 20 or so you can see all fuses and relays shown, at the end is even a component location view
http://shark.armchair.mb.ca/~dave/BMW/e34/

If the doors continue to lock or try to lock although the doors are locked, then there is something wrong with the locking system, simply speaking : under the rear seat there is the GM which is the brain for the central chassis electronics, and that sends the orders to the module sitting next to it, which is the relay module, which executes the orders.
GM/RM are also for central locking, interior light, wiper/washer system, electric windows, electric sunroof etc.

[paperplane94]

Have the battery tested properly. A poor battery can cause strange issues.

[Steelbasher]

Thanks Paperplane94, I think I will probably have to change the battery as I've had it charging for nearly 24hrs now and the indicator hasn't made a move from black. Though connecting my multimeter to it seems to say it's putting out the correct charge to still be good it may just be knackered.

Shogun, I can feel where the relay is clicking and it is in one of the two black boxes along with the fuses under the seat (about 1" by 8" in approx size) which I cannot identify until I have a workshop manual. This unit seems to wobble about a little and would likely be easily removable (if I knew how without damaging it). I am unaware of anything wrong with the wipers or the washer pressure but as I have the battery out to charge at the moment I am unable to test these. I believe the wipers were working fine before though.

Also I had noticed that the LED displaying the mileage does not display correctly, I'm hoping this isn't a problem with the computer but rather a problem with the display it's self. Any ideas or experience on that one?

[The Night Rider]

"Shogun" probably knows a lot more about this but as far as I know the LCD dead pixel problem is caused by a bad ribbon cable, which connects the instrument cluster circuit board to the LCD display. This cable naturally deteriorates over time and sometimes the pixels come back for a while only to disappear again.

You can buy replacement ribbon cables.