Boy, you're in for a major repair! Hope you're up to it.
Look on the "B" pillar for the door switch. The "B" pillar is the one with the latch, next to the seat backrest. The switch's mounting plate is shaped like a tear drop and is held on with a single screw. In the middle of the plunger you'll see what looks like the round head of a nail. Next to it is a very tiny slot where you can insert a small pick. Use that to pry that nail head out. You can remove it all the way, but normally you're supposed to just pull it out about 1/4" and leave it there. It will self-adjust the first time you close the door.
The problem is with repeated slamming of the door, that "nail" goes in too far and over-adjusts. That lets the plunger come out too far to the point where the switch turns on intermittently when you drive over bumps in the road. To prevent that from ever happening again, I pull that nail all the way out, then install washers on it so it can't over-adjust. Three "M5" metric lock washers fit perfectly, but for the crowning touch, I use a bottle of black touch-up paint on those washers so they aren't so easy to see. Do the same thing on the other side of the car too.
This entire repair takes just two or three minutes, plus the time to paint the washers.
SPONSORED LINKS
Wednesday, June 10th, 2015 AT 9:08 PM