535i electrical question

I own a 90 535i and am experiencing some problems with my headlights and taillights going out periodically while I'm driving. Has anyone seen or heard anything about a problem surfacing with the electrical syst

Check this link

http://www.bmwe34.net/e34main/maintenance/electrical/LKM.htm

I had a similar problem on my 1990 525I when I first got it. It turned out to be a light control module. The dealer ship charged me somewhere between $180-200 for the module plus labor to replace it. I think its located in the fuse box in the engine compartment. Its a long black box in the fuse box compartment that got replaced.

I had the same problem on a 525SE. The problem was the light vontrol module in the fuse box. However I did not need to replace it. Once removed, the outer cover comes off easilly. Inside there are a group of seperate relays all of which controll different individual lights. On mine, the was a solder joint into the printed circuit board that had vibrated loose. I simply melted the solder back to the pin and its has been fine since a year ago and is still going strong. If you plug the unit back in with its outer cover removed, you can use something non conductive to manually switch each of the rrelays in turn (with the ignition on) and when the effected light comes on you'll know you've got the troublesome relay. Then just follow all the printed circuit on the board for this particular coil and you'll likely find your problem.