Tail light problems

[wlerner]

My 1990 750iL claims that there is a problem with the tail light. I have checked all the bulbs and they are all functional. The tail light on the left side of the car is out. and I am unable to make it light. Does anyone have any suggestions?

Warren

[ksilva6069]

I was having problems also. Check the contacts. I found one that was rusted. I just got a new socket for $10. It did not end there. It kept doing the same thing so I switched it with the other side. Then that side stoped working and the bulb does not look blown. I just replaced it and so far so good.

[webb747]

I also had similar problems with my '98 740iL. I bought the car a year ago in May, with 45k miles on it. Periodically, the CHECK BRAKE LIGHTS warning message would come for a few days, then go off. This happened 3 - 4 times over the 16 months that I've owned the car.

I checked all the lights, and they appeared to be operating OK. I re-seated the plastic bulb holders and bulbs - nothing seemed to make a difference, so I finally ignored the warning message.

Two weeks ago, the right brake light burned out. In the process of replacing the bulb, I found there had been electrical arcing between one contact on the plastic bulb holder and the metal contact on the brake light housing. A small hole (about 1/16" dia.) had burned through the metal back of the brake light housing, in the detent that helps the plastic holder snap in place.

I used emery paper to clean off the bulb holder contacts and the burned area of the brake light housing. However, the light still didn't work unless I backed off fully seating the bulb holder, so the electrical contact hit on the ridge of the detent - when fully seated (clockwise), there was no electrical contact. This seems unusual, since the contact on the bulb holder is wider than the hole, but the light wouldn't come on until the holder was backed off. So far, so good.

Hope this helps.

[MNC012]

I have the same problem on my 1995 740i, been getting messages, and this morning the whole tail light assembly (the left side) stop working, the brake, tail, signal, back up light... NEED HELP!
P.S. i am about to let my car roll off a cliff....

[DutchDaniel]

@ MNC012: I've just bought my third E38 730i (1995 European model) and have heard -and experienced- it to be a common problem on E38 models that the lightmodule dies or goes crazy. Non of the lights have fuses, they are all controled by a computer: the lightmodule.

Normally, in case of a dead bulb, short-circuit or wiring problem: the lightmodule just quits putting power on that wire (so acts as a fuse) and sends a warning to your check/control on the dashboard. It will automatically restore power if the problem is solved. But the lightmodule can also go berserk (due to leaking rainwater, wet/snowy feet, age, etc). On my car, the head-lights went on and off at their own will and suddenly refused to go out at all. When the problem progressed over time, blinkers started flickering fast at random, the check/control-unit kept screaming constant light-errors and the frontal fog-lights wouldn't work, no matter what I did. The local BMW-expert said it is a fairly common E38 problem, especially in the early models (M60). I changed the lightmodule myself and the problems vanished like snow in the sun... There's no point in repairing the lightmodule, just get a (second-hand) replacement ("try before you buy" may come in handy). Fitting it is not hard, but takes some patience and small fingers.

The lightmodule is located on the passenger side, near the door at foot-height. Gently dislodge the passenger-door inner threshold-strip, then the small vertical strip. Take out the bottom-cover of the glove-compartment (screws, from below), don't forget to disconnect the gong-plug before ripping out the cover. Then peel away the insulation, starting from the door-side. Just inches from the floor and door is the lightmodule (a box of about 3 x 10 x 20 centimeters).

Make sure the ignition is switched off (take out the key to be safe). Disconnect the light-module's cables with prudence, using the snap-on/off system (hardest part of whole operation). Reconnect the new lightmodule and try your lights BEFORE putting all the parts back. Just in case... :-)

By the way! Replacing the lightmodule can have side-effects... The mile/kilometer-reading on your dash is stored in this module. So replacing it can result in showing the mile/kilometer-reading of the car where the new module comes out of (if that car drove more miles then yours. If the donor-part has a lower reading, then your own reading will be maintained). Also a very small red light may appear on your dash, indicating "fraud" with the mile/kilometer-reading. Personally, I don't care about that small red light, but if you want that fixed too... go to a BMW-dealer, put the car on a main-computer and have the new lightmodule programmed into the car's software. That'll cost you dearly though...

PS: Never-ever roll a 7-series off a cliff, please! These cars are driving far too good to just send 'm over the edge... :-)

[elogan98]

I'm a newbe, I have a 1988 735i and I have no tail lights at all, I changed the fuse and the Tail light switch.... I NEED HELP

Thanks in advance...