I have a 1998 Jeep Grand Cherokee. Recently the interior light has started going on and off when I am driving - as though a door is not fully closed. I close every door (including the rear door) carefully but this is still an issue. As well, the alarm goes off in the middle of the night for no apparent reason. I am going to look at the fuses but any other ideas or direction is appreciated. Thanks.
I had the same problem with the interior light on my 98 Ford Windstar. It turned out the driver’s door switch needed cleaning. The door switch on the Windstar was built into the door latch. I sprayed CRC Electrical Contact Cleaner into the latch mechanism while working the door handle.
Most door switches are located on the body by the front of the door. Spray some contact cleaner or WD40 into the switch and work it in by depressing the switch manually. Hopefully it’s something simple (and cheap) like this. I can’t speak for the alarm going off, but I bet it’s related.
Good luck,
Ed B.