Today I've been working on fixing the Door Ajar problem that's developed in my 2002 ranger extended cab. I haven't made any progress taking the main doors apart and testing the switches. Doing a little research on the forum I learned that the door ajar wiring is tied in with the dome/instrument dimmer. Well that's interesting because my instrument dimmer was never worker properly. It dims the running lights instead of anything in the cab, and if I turn it down too low, the fog lights won't function.
So I have a few questions:
+What's the way to determine which door, if any, is sending "door ajar"? I'd rather not take the back doors apart, and check the wiring on each door.
+What's the deal with my dimmer?

 

I started with the rear passenger door and shot W40 up into the latch. I then opened and closed the door several times, working the latch. Then I went to the rear drivers door, did the same thing. Mine turned out to be the rear driver's door responsible for the Door Ajar. I then did both front doors.

Your dimmer problem, I have no clue. Sounds like someone jacked up your wiring.

 

I've got the door ajar fixed. It was the switch on a back door. So just my odd dimmer problem remains

 

here is a link to wireing diagrams that is very helpful,,,keep it and pass it along,,, _____ Search Wiring Diagrams

 

thanks for the wiring reference. gonna bookmark that one

 

Been playing around with this more- wiring diagram in hand. I've discovered that it works as it should with the truck off. The problem only crops up when the ignition is on.

 

Been at it this whole easter day. Obviously there is a short somewhere. I isolated it by pulling likely fuses. (Diagrams helped). By pulling fuse #20 (radio and GEM), I fixed the problem. I don't use the stereo, so no need to pursue further. It's probably like Jk___ said: the previous owner messed up the wiring by doing a hack job of a radio install.

 

i thought the GEM powered the power windows and locks,,,hhhmmmm guess i am mistaken

 

At least 4 fuses say GEM. I was getting odd functionality taking them out- but this one seems okay to remove.

 

Seeing as how you seem to like trouble shooting & turning your own wrenches, if you have a ELM scantool, have it scan for trouble code clues & post up All code Numbers, as they can help focus a trouble shoot.
If you don't yet have the inexpensive ELM scan tool, or aren't running FORScan or the like diagnostic software, have a read here about a good tool for our electronic tool box. https://www.ford-trucks.com/forums/1...-scantool.html

Let us know what you find.