Airxcell Thermostat Reads 99 with AC On

[PappaJohn]

The main thermostat by the door reads the temperature normally when nothing is operating. If I set it to cooling the room temp stays where it was for a few seconds, then the display flashes off and on a few times then the display goes to 99 F and stays there as long as I am in the cooling mode.

I replaced the unit with a new one and it does the same thing.

Any ideas?

[ncitro]

The main thermostat by the door reads the temperature normally when nothing is operating. If I set it to cooling the room temp stays where it was for a few seconds, then the display flashes off and on a few times then the display goes to 99 F and stays there as long as I am in the cooling mode.

I replaced the unit with a new one and it does the same thing.

Any ideas?

I'd suspect maybe the board in the AC unit, but I'm not sure the Coleman communicates with the thermostat the way the Dometic does. If I remember right the thermostat had a connection for it's own 12v power on one of the wires that ties together up in the ceiling unit along with the board connection (the 12v feed comes in on a separate 14 Gauge two conductor wire). I'd look for that splice up in the ceiling and check it.

[PappaJohn]

I had the dealer replace the thermostat while the rig was in for some other warranty stuff. I had never checked the wiring before which I did this morning. It was wired incorrectly with one of the AC leads going to a remote sense terminal. All is well now.

Thanks for the inputs.

[ncitro]

I had the dealer replace the thermostat while the rig was in for some other warranty stuff. I had never checked the wiring before which I did this morning. It was wired incorrectly with one of the AC leads going to a remote sense terminal. All is well now.

Thanks for the inputs.

That's great! Glad we could help!