On a 2001 supercrew,we did the wd40 deal first. Then changed out the door sensor switches on all 4 doors. Still no luck and the door ajar/buzzer and inside lights come on most of the time.. We have adjusted all the door latches , checked fuzes and relays but again no fix..

Anyone have any suggestions? The truck has an auto start and auto door locks.. If you sit in the truck and keep hitting the door locks, the problem will come and go.. Can it be a door lock actuator?

 

I would try disabling the auto start system to see if thats the problem. If thats not it could be a GEM problem.

 

I will take a look at that.. We gave up and took it to the dealer for a diagnosis. They want 300 bucks and claim it to be a wire grounding out inthe A pillor to driver door connection.