Glad you got it figured out!
When I read these old posts with no apparent resolution, I get a mental image of the owner sitting outside in the cold with a dead truck.
Very sad...

 

Don't the newer trucks kill the lights after a few moments when the truck is off? I have a similar problem and I think it may be the door switch as well. I got out of my truck with the door open and out of nowhere, the chime that alerts you to an open door went off about 20 seconds after the door was already left open. It's like it detected the door open again.