1990 735iL Tail Light - BMW Forum

razimm · 07-16-2007, 08:39 AM

I need help with a right side tail light problem. (The left side works fine.) There is only 9 volts at the bulb terminal, without the bulb, which then drops to zero when the bulb is inserted. The fuse is good and measures 12 volts, so somewhere I think there is a poor or corroded connection. The tail light wire has only 9 volts where it enters the trunk. I don't have a wiring diagram and would appreiate any suggestions on where to start looking.
Thanks, Rudy

richard morris · 03-27-2008, 09:12 PM

Hi, my RHS tail light would go off unexpectedly, and then come on later. It was suggested that the mustard coloured relay in the fuse box is the problem. I followed the given instructions, re-soldered the lugs on the back of the resistors and so far no more problems. the link for the info is
E32 Soldering fixes - LKM & Mustard Relay

All the best Richard

beamers4life · 11-10-2009, 07:15 PM

If it isnt the relay or the lkm I would check your trunk ground i had a very similar issue on my 1990 735il except it was my low beam headlight it proved to be a ground issue. If you need a quick fix or cant find out what it is run a jumper wire from one tailight to the other.