courtesy and map lamps won't turn off as they should in 30 seconds
courtesy and map lamps won't turn off as they should on 1999 Cadillac DeVille
Do the light turn off after about 20 minutes? That is when the battery rundown protection kicks in. The Body Control Module controls the courtesy lights. I would suspect that one of the door inputs is telling the BCM to keep the lights on. Using a scan tool to read the date stream from the BCM may help in determining which input is keeping the lights on. I may be the case where each door switch will need to be disconnected one at a time to try and isolate the fault.