As of lately the door ajar light on the passenger side door has been sticking leaving the dome light on and keeping my alarm from activating sometimes when parked.

Is there a sensor that tells that the door is closed that can be oiled or adjusted? I'm totally in the dark on this one.

 

spray some WD40 in the opening where the guide bar goes in and out of the frame.

Remember on older cars that thin little **** on the door frame that controlled the light? The door pushed it in when closed and let it pop up when the door was open?

These are inside the door frame now as opposed to being outside.

 

I sprayed it with some oil and also found a wad of paper towell in the locking mechanism. Anyhow it seems to be working now. Thanks!

 

This is a VERY common problem amongst F-150 owners... WD-40 or similar always seems to do the trick!