one yellow, one black

 

there are two swing doors.

 

This is correct. The door ajar switch 'grounds' the circuit. What Spell did would still work. Shorting the wires together accomplishes the same thing because you are simply bypassing the switch. BK goes to ground, YE/BK goes back to the BCM, and so the circuit is simply shorted to ground.

wire 1: Yellow with a black stripe
wire 2: solid black

right? I think you got the correct wires but clearly the switch isn't the problem. So you would go to the schematics and find the circuit for the side door (instead of the front door like I originally did)

Test continuity between BCM - X6 - pin 14 and ground. (see the connector drawing in my first post). You can also probe @ connector X318.

With those schematics you have enough information to isolate the door ajar problem now. Post here if you run into any trouble.

locking/unlocking problem:
Before you can troubleshoot this, you'll first need to be able to reproduce the problem in a predictable way. Is it completely random or do you think there is some pattern or trigger to it? Certain gear, speed etc. or vibration.

 

The unlocking/locking only happens with the "right rear door ajar" alarm

 

OK and you said that happens every 3-4s the entire time you're driving right? That sounds like you have some faulty wiring so you need to check it like I described. Also check the switch ground (G348) which is screwed to the B pillar.

Oops I forgot to give you the link to the drawings.
https://www.gmupfitter.com/pages/body-builder-manuals
(2013 is same as 2012)

 

I know this is an old thread but I had exact same issue. After tearing dash apart, I found that previous owner had installed a fleet GPS monitoring device. After removing it and repairing wiring they had spliced into, the problem went away. Random issues with interior lighting and blower fan also went away. Hope this helps someone else because that constant dinging almost drove me crazy.

 

* Update: symptoms came back but slightly different. More digging and I found a speed limiter installed also. Took it out. Hoping problem solved completely now.

 

Hey K,

So I just bought a 2016 2500 and it used to be a service vehicle for a fleet. I'm wondering If i'm in the same boots you were. Any chance you can give me a little more detail into how to figure this out? I'm not much of a mechanic but I'm competent enough to save a couple bucks here or there. Thanks in advance!