HELP! I am the origninal owner of a 1992 325i with 150k in excellent shape. After some some minor body work this winter when I went to fetch the car the interior dome light and rears would not shut off no matter what the position of the switch. The shop spent several hours attempting to fix the problem, including replacing the door switches. All to no avail. They eventually claim to have found some corrosion on the bulb dome light bulb and the removal of that seemed to fix the problem. The logic of this escaped me at the time, but I was just happy to have the car back and working. The issue has recently returned and I checked the bulb and it is clean. The bulb socket is live even with the "switch plate" pulled off the "backing plate", in fact ALL three of the bulb circuits are live, leading me to think the bulb is not the issue, that the original shop "fix" was a coincidence and that there must be a short somewhere. Any ideas on how I might begin to track this down or where the short is most likely to be? I'd hate to be paying shop rates and my own fuse in the recent heat is pretty short. Thanks for any help.
Dome light troubles are nothing new to E36 3-ers. There are a lot of electrical connections to the harness for the dome lights -- And a bug in the alarm or the failure of the door switch can cause poltergeist-type occurences ! What you are describing is usually a microswitch in the door -- it might not be (you said the shop replaced yours). The other thing to do is to drop the switch from the roof liner, and inspect all of the wiring. An inappropriate ground or "short" could cause your lights to stay illuminated. 1. Disconnect battery for 30 minutes + . THis willreset the computer and alarm. Might alleviate symptoms, but not a fix. 2. Have a professional BMW mechanic (or yourself with the aid of a Bentley) check the doors for their fitment, alignment, sensor actuation. You can trouble shoot by playing with the sensor actuators in the door frame withy our fingers. Push in and release repeatedly to test if they shut the light out. If they are defective, replace the door switch(es). 3. Time to look for inappropriate grounds or mis-matched wiring. You need a bentley service manual and a multimeter and a case of Beer. Good luck.
I had a similar issue on my '95 and it turned out to be that the door latch that houses the microswitch was not aligned correctly. They were brand new latches but simply were not lined up correctly and the interior lights would stay on sometimes, or they would turn on and off as I drove down the street (that was always exciting at night). Even if they are new, check them manually to make sure they are not your problem.
