QuestionGood Morning Rob. I have a 1998 cadillac deville. The Door ajar light will not go out when all doors are closed. At night when i open the door, the interior light does not go out. Daytime the interior lights come on and go off fine.
AnswerHello,
Could be a couple of different problems. The first I would be looking at is a defective door jamb pin switch if so equipped. The switch is a plunger type that goes in and out when the door is closed. With the driver's door open looking forward towards the fender half way up the door on the body you should see the switch. There is one per door. If one of those plungers is not going in all the way, even though the door is closed, the dome light will stay on. Theses switches are relatively cheap and easy to change. Its just a matter of unscrewing, removing the wires, reattaching the wires and screwing the new one in. I would suggest loosening the driver's door switch 1/4 turn first to see if you can put a little more closure on the plunger. If problem persists, the same on additional doors one at a time. Between doing this, say a one day time span for each, tighten them back the way they were. In other words, you are trying to see if you can isolate this issue.
What you could do as well is have the car running where you can see the door ajar light on as you describe and start with the driver's door and leave it open an push in on the driver's plunger as hard as you can. If the light stays unlit, you know the switch is bad and needs replaced. Close the driver's door and do the same if the problem was not at the driver's door.
It could also be a module and the only reason I state if so equipped is that although GM still uses door jamb switches, on some they did not an I o not remember anymore on your 1998. The door jamb switches did fail, and especially if you are located in the rust belt.
Take a look and if you see the plunger switch, try my suggestions and get back to me.
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