Sometimes interior light problem

[Canada Kev]

My interior lights seem to be a little confused. On seemingly random situations, the interior lights won't shut off when the door is closed. They must be manually switched off. Then, some time later, they will start working properly again. I cannot recreate the circumstances when this occurs. It just does it whenever it wants.

The things that SEEM to not be the problem:
-door switches/pins
-interior lights
-trunk switch and light
-alarm module
-seat belt switch
-glove box switch and light

As well, when this is happening, the alarm won't arm when switched on. Except for the trunk. It will arm and work properly, so this leads me to believe that the problem doesn't lie with the trunk circuit. The alarm is supposed to arm with the doors and interior lights on, right? Maybe it won't activate until the light circuit switches off (door closed). Just manually turning off the lights doesn't work.

So that I won't have to go through this whole system with a meter and wiring diagram, has anyone seen this before? Its not a big deal, as I can just turn the lights on and off manually, but I would kinda like everything working the way its supposed to.

Thanks for your help.

[dipso]

Make sure your door is making contact when it closes. My passenger door was not pushing in the switch enough.
I put a self sticking, rubber bumper on the door where it makes contact with the switch. Like the kind used on furniture or cabinet doors.
Problem solved.

It doesn't sound like that is your problem. But if it works when you press it with your finger and not when you close the door, it might be.

[Canada Kev]

I pushed them in by hand. No difference.

[Rich Lambert]

I believe the interior lights have an in-sequence ground that terminates at chassis ground and then from one light to the other. Pop the lights out and check for a good connection or corrosion on the light or the wire terminals. The brown wires are ground. Actually, check all the light terminals and wire terminals for a good connections and corrosion.

[kidrock]

I just repaired my interior lighting problem recently. It sounds as if you have a ground problem. Have you tested both door switches, or only one side?

The door jamb metal which the switches screw into are part of the ground itself. I would recommend cleaning both switches very well with a brass brush. Also need to clean very well the hole where the switches screw into. Put a dab of di-electric grease on the contacts and gently re-assemble.

Let us know how this works out.

[dshepp806]

I agree that it is probably (possibly) ground related. Tear 'em apart and clean (any of 'em). They're ALL worth the look,..not to mention that it can be measureable if you can induce the problem.

Good Luck!!

Best,

Doyle

[Canada Kev]

I think my biggest problem here is that it won't act up when I want it to. The problem seems to have taken a break and is now not showing itself. The thing is that it works FINE right now. All lights and switches work the way they are supposed to. I took a cursory look at pretty much everything that comes to mind that might cause this problem, but was hampered by lack of time and resources to properly tackle it at the time. The list includes lights, door switches, alarm module, trunk light/switch, seatbelt sensor... Maybe over the long weekend, I can take things apart and inspect closely.

I was under the impression that 911s had ground switching circuits. Is this not the case?

[arbita1]

Try this...

Pull the lights out and put electrical tape over all the connections.

I don't know if you have a coupe or a targa. On my targa the interior light in the targa bar would sometime ground itself to the bar and stay on regardless of door switch position. I guess the clearances are kind of tight in there. Someone recommended putting electrical tape over the connections and it seemed to work.