I had been using electrical contact cleaner and WD40 on my door locks. Sometimes it would work for weeks, other times not quite so long. I got tired of doing it over and again, and decided to take my driver's door apart to see what the door ajar switch looked like. While I had it apart, I decided to cut the wires to the switch... black, and black with yellow stripe.
Cutwire.jpg
Well... that one is never gonna give me a problem again!
My Haynes manual although pretty good has a diagram that points to a GEM module, and all the switches go through it. I figured that it would be much easier to determine which of the switches is not working by testing it there, rather than by opening up each of the doors and testing the switches individually.
This is my understanding...
When the driver's door, the passenger door, and the tailgate door is open, each of their switches shorts to ground. The sliding door is different.
If the door ajar light is on... one of the doors switch is shorted to ground, or the sliding door is open.
So if all the doors are closed, and the interior lights are staying on, then we need to know which switch is shorted to ground. This way we can concentrate our repair on the bad switch.
We can test the three doors, and if they are good, then it is the sliding door, or maybe the GEM module itself. OK so here we go.
The GEM module is located to the right of the steering column up behind the dash. There are three connectors to it. The one we want has eleven pins accross.
Gem.jpg
Next we'll want to test the pins (that are the input from the doors) for each of the doors to see if it is grounded. If it is grounded that means THAT door's switch is faulty. SO we set up our digital voltmeter to Ohms and set the neg terminal to a good ground. Next we'll test to see if the various pins are grounded. (If they have continuity to ground that switch is bad)
GemPinOut.jpg
OK.. so this is a real quick test Close all of your doors... check each of the door's pins... But NOT the sliding door, If it is grounded, that switch is faulty.