E53 X5 interior lights randomly going on/off

[Jake the Snake]

I bought our first X5 3 months ago and love it. It’s a 2006 with the 4.4L and 122k miles. All was well until my son gave us an Alpine backup camera for Christmas and installed it for us the same day. The cam was fed into the existing Pioneer stereo and works great. However, at 5am the next morning, the factory alarm went off. Nothing was disturbed so the car was locked up again after the alarm was cleared. A 1/2 hour later the alarm went off again. I live in the country so nobody was messing with it. After the alarm was cleared again, I went to disconnect the battery and the rear hatch release wouldn’t operate. I eventually disconnected/connected the battery to reset the electronics and the hatch controls worked. Later, on the way to town, I noticed the interior lights would come on and go off randomly.

Back at home, the cam was disconnected, but the problem persisted. Apparently my son tried to hook up the camera power wire to the tail light wiring to get power, not realizing that it carries a digital signal and is a bad idea. This was all done without disconnecting the battery. When he couldn’t get a proper voltage, the power was obtained from a spare terminal on the power block near the battery. The taillight wire was spliced with solder and shrink tube and works fine.

A Bentleys manual was bought but doesn’t address the problem, nor provide detailed schematics...only wiring diagrams. The X5 acts like it has a faulty door latch or interior light controller. I have no idea how to test the latches’ Hall Effect voltage w/o removing every freaking door panel. But I believe this condition is what is setting off the alarm. The X5 remains disconnected from the battery so I can lock it and is basically useless until this problem is resolved.

Any suggestions, short of taking it into the dealer, would be heroic.

Thanks

[ragdollop]

Hey did you ever figure out what the issue was? I have a similar issue with a 2006 E53 X5 3.0l and it has the interior lights randomly coming on and off. It also has other electrical issues and I believe they might be cause by a faulty battery or alternator.

[//m320is]

I would look into the tailgate latch, they have a tendency to wear out fast, I have replaced mine twice and I have noticed that when driving down the road the hatch lights coming on and I would get the "tailgate open" on the dash. I would pull over open and shut the hatch, sometimes it went away, sometimes it didnt, until I finally replaced the latch assm.