735iL Low Beam Lights going out?

Anyone ever have this issue?

1992 735iL. Turn on the lights and the low beams will stay on for a while, then just drop out. Sometimes they come back on, sometimes not. Oddly enough, when I switch on the brights, they come on just fine. Could this be a switch issue or is their a module like the brake light circuit that is dying?

the issue should be a relay thing.

The low beams have two elements and each is controled by a different relay. When you turn to high beams it is a different light element and relay.

Here is an e24 diagram for a visual reference.

http://members.roadfly.com/kcroncarter/etm136.htm
http://members.roadfly.com/kcroncarter/bmwetm136.jpg

Later,

Well thanks!

I never figured on getting such a detailed explanation! Thank you very much! Went to my service guy and he pulled the relay and sure enough, thats the problem. When I bought the car (used about 3 months ago) they put in a remanufactured one because the brake lights decided not to work. He's going to replace it on Saturday.

Thanks much!

Fixed.

Replaced with another LKM (remanufactured) and works fine. Just have to see how long it stays working. Didnt cost me anything, the mom&pop dealer I bought the car from cover it. In California, they cant sell a car with non-working lights and safety.

Now all I have to do is get some new ellipsoid lights! :naughty:

Brings back memories of my 88 735iL... The most common culprit is the mustard colored relay in the engine fuse box. The LKM is usually replaced first because it's very expensive and more profitable but usually the problem is the mustard relay.

Good luck!