Questions and Answers

Mercury Cougar Interior Lights Stay On Q. Hi, I have a 1988 Mercury Cougar, 6 cylinder automatic transmission with about 90,000 miles on it (rebuilt engine). Everything seems to be power, doors, locks, seats, etc. The interior lights will decide at random to stay on and drain the battery. It will run for a week or two fine and then just all at once the lights won't go out.

I have checked the dimmer wheel on the dash and it's not that. I shut the doors tightly, thinking maybe if they aren't closed tight, the interior lights wouldn't go out. But the doors are closed tight; just can't seem to figure out the problem. Any suggestions?

Thank you,
Bryan

A. The switch that turns on the interior lights is located either on the B pillar door jamb or incorporated into the door latch assembly.

Depending on the interior lighting system used (there were three), there is a Courtesy Lamp Relay located in the trunk, under the rear shelf.

Either one of these may be going bad. But personally, I would lean more towards the door switch.