AC or Thermostat problem

[Steve Sullivan]

I have a 2007 Challenger 5th wheel 35CKQ with either having air conditioner or thermostat problem not sure which. When the AC is turned on it runs for a short time but pops the AC breaker, but the furnace tries to run at the same time. I have checked all fuses / breakers. I have double checked the connections to the convertor and tightened any and all loose connections. Another thing I've noticed is the AC / heater has issues when the center lights to the living room will not turn on. It seems when the lights are working correctly the AC works correctly. I have disabled the wiring to this light switch and tried running the AC again, the same issue with the AC and furnance trying to run at the same time happens.

[Richard W. Cobbs]

When you post AC/heater, I assume that you have an AC with an electric resistance coil for heating. If they are running simultaneously, then you will pop the breaker as each draws a heavy load.  The only way that they would run simultaneously is if there is an internal problem with the AC/heat unit.  This problem is most likely in the switch, or possibly faulty wiring.  Did anybody mess with it?.  You mention the ceiling lights not working properly, but usually they would be 12 volt, not the 120 volt that the AC unit uses.

[Steve Sullivan]

I think the thermostat is faulty. Have ordered a new one... Why the lights seem to not work at the same time the AC still boggles me. If thermostat doesn't fix my issue I will have to take back to dealer to get it looked at

[Steve Sullivan]

We had a grounding issue. Once we connected grounding wir in AC to a better connection it fixed our problems. Thanks

[Bruce]

A co-worker had something similar to this with his new trailer.  The solution was to make sure the thermostat was in cooling mode only.  Once he did that he no longer had the problem.