Coach rebuilt - thermostat gremlins

[jonohio]

So I've got a 2004 Mountain Aire pusher that had a fairly isolated refrigerator fire. The rebuild is coming along nicely and i've got most of the 120V and 12V sorted out, but the thermostat repairs are leaving me stumped.

I've read dozens of threads and I wanted to get everyone's thoughts, here goes:

In this coach the HVAC consists of two roof ACs and hydro hot, with a single over the driver cabinet thermostat. The thermostat is not powering up.

Testing:
1. I have 12V and 110V at the front AC.

2. Both modular plugs at the front unit control board have 12VDC on the RED wire.

3. 12VDC is present at the thermostat RJ11 plug, but on the green wire.

4. I understand with Newmar's ducting there is probably a female coupler somewhere in the ceiling, but I can't figure out how pins would shift like they appear to be.

My thoughts/quetsions:

1. Does anyone know what the duo-therm modular plug individual wires purposes are? Is red hot and neutral black? What about the other wires, are those data lines? I have the troubleshooting guide but it doesn't indicate this.

2. Testing with my powerprobe tells me that none of the modular plug pins are going to ground, is that normal? It looks like yellow is open (perhaps that is the ground?)

3. I intend to try to manually plug the thermostat into the front AC unit but i can't do that without removing the control board. Anyone know which plug probably goes to the thermostat? P1 or P2? I can trace it if need be.

4. I wonder if the fire shorted out something and the AC board (or female coupler) fried and split the pairs. Or may be Newmar just used a non-standard pinout?

5. The Fridge fire is nowhere near the front AC/thermostat run, but it did melt the RJ11 rear AC to front AC cable. Perhaps that has affected things.

6. I also can't detect a ground on the run coming out of the front AC and going to the rear AC.

7. I have yet to validate a 12V neutral going to the AC, after all this typing, maybe that should be my next step.

Ok, my A.D.D. is running rampant tonight, curious if i'm on the right track here.

Am I missing anything here?

["007"]

If you look in the QT's 1 & 2 link you will find the wiring for the AC's to wall control over your drivers seat.
All three are connected by tel wiring coeds from AC control boards to farthermost. The control boards also have dip switchs that need to also be set if they were changed.
All the links below in my signature have answers for your Newmar.
This link has important info also.

[jonohio]

Thanks 007. I’m well aware of those details. I don’t think you actually read my post.

I’ve read through all your reference material but can’t find the level of detail I’m looking for. Maybe I’m missing something....all I find that’s relevant is the rj11 pinout, which I already know. Nothing regarding my scenario or my questions.

["007"]

The front AC feeds the rj11 to the thermostat control, from its control board.
There have been some long discussions for these rj11 cords some of the threads are in PROBLEM SOLVERS found in QT's #3, Brucecila is a expert on these AC's.
We can also do a Newmar search for your problem.