late GMT400 interior lights wont shut off like a door is open.

[squaredeal91]

1999 K1500 suburban interior lights will not shut off unless I unplug the fuse. Dome override button doesn't change anything witch is weird. Tried a different switch and no change. vehicle been sitting 4 years. Fixed lots of things and did lots of maintenance to get it back on the road. Runs and drives great! But now suddenly lights stay on.

When driving with lights on the chime screams at you even with light fuse out. so night driving is NO. Fuse no 3 controls the lights. Assuming it's not the switch at this point.

Either a shorted wire or bad door switch. Driver door is ruled out because I can leave the key in ignition ant it will scream till I close the door and it goes away. So it's in one of the other 5 doors?
Anyone els have something similar? Probably not related but alternator just died too.
Hoping someone else has some good ideas. I'm probably going to have to check all the switches tho.

 

[Doppleganger]

I always had issues with the door jamb switches. With them sticking and then corroding both.

 

[PrairieDrifter]

Door jamb switch or a grounded wire. I've seen the wire come off the door jamb switches and hit ground too.

 

[squaredeal91]

I'll pull the switches and see what I can find wrong. Thanks!!

 

[75gmck25]

Interior lights should have a constant power orange wire running to them, and there is also a white ground wire (but its not grounded). The light sockets and housings must be isolated from ground, so they have small spacers to keep them from grounding to the body. Basically it's a light socket with white and orange wires running back to the dash area.

The door switches are all interconnected by white wires, and it should also run to the dash switch (at least on older trucks). When a door is open it grounds the white wire and the lights turn on. Simple circuit, but different than most other lights on the truck.

 

[Robert Bare]

Did you try opening a door, one at a time, and pushing in that switch, see if lights go out? You also will be able to tell if it fell apart, as==no spring pressure.
Be aware most of those had a interior lamp control module, and it then takes 30-45 seconds for the lights to dim and go out.
Also, not sure on this, but I think some had a switch at the back, to turn on all interior lamps, may have been built into the rear topmost lamp.

 

[squaredeal91]

I tried pushing in each door switch with key on to force them off so I didn't have to wait for timer. Still they stay on. However I just thought about when this started and I think it Started right after I swapped out center interior light. Maybe I should remove that first then go for doors.

 

[Robert Bare]

YEP!