Rear windows won't roll down on 4 door.

[Zerrrro]

New guy here, just bought a '90 Delphin 4 door. One issue I'm having is that my rear windows won't roll down from the switches in the console or either door. I've done some research and found that there is a rear window lockout switch somewhere, but I can't seem to find it. Of course the owner's manual is missing and the only mention of a rear window lockout in the Bentley is in a wiring diagram.




This one is inside the glovebox on the left side. Sorry about the blurriness, its basically just two holes with a + and -.



Any ideas?

[Gregs///M]

The glovebox socket is for the OEM flashlight. I would pull the switches for the rear windows and clean the contacts. Heck, might as well pull all the switches and disconnect switch and clean all contacts.

I've even gone to far as to open each switch assembly up and clean inside there. After 20+ years, the contacts literally become black.

Also, consider cleaning the grounds for the window circuits. They are located above the brake pedal on the bracket that holds two 10MM nuts. Upper nut is cluster grounds, lower nut is windows and other interior grounds.

Performing all these cleanings will not only make your windows work, they will drive them up and down faster. (assuming your regulators and motors are OK) GL

[Zerrrro]

So I took the switches out of the rear doors to clean them, and the left switch wasn't even plugged in lol. I cleaned them with some electrical cleaner and plugged them in. The one left one now goes up and down without any problems. The right one still won't budge though. I'm guessing the next step would be to remove the motor and attempt to clean it up?

I wasn't able to locate the grounds you were talking about though. It's a bit of a mess under there and I don't really know what I'm looking for. I only removed the very bottom cover with the cutouts for the pedals, do I need to remove the cover directly under the steering wheel as well?

Thanks a ton for the info btw.

[theBAYsics]

im in the process of trouble shooting mine as well. 4 door, front windows work, rears dont work.

im following the wiring diagram in the bentley manual. the upper left button is a rear window lockout switch. i pulled it out and test for voltage and continuity, both check out.

now just gotta check the rear window console switches and the rear switches on the door panels.

hopefully its just a dirty connection, i doubt both window motors would be out.

[Zerrrro]

Yeah after getting the left side window working, I confirmed that that square button is the lockout switch. If it does end up being your motors I found a how-to on cleaning and servicing the motors. http://www.crunchyfrogpro.com/bmw/e3...or_repair.html

[theBAYsics]

thanks, bookmarked for reference.

[nando]

it's probably the switches. My rear switches are getting pretty bad, I can barely move the passenger rear window at all, and the drivers side will only go down if I hold the switch just right..