AC thermostat

[La.Paul]

I have a 2013 Navion 24m and I installed a fantastic fan two weeks ago and while I was doing this the AC seemed to be working correctly. This past weekend, I was putting in a coax AB switch in the cabinet above TV, and I noticed AC not working correctly. It would turn off shortly after starting but if I adjusted the thermostat (really just pressed a button, didn't have to change the set temp) , it would run and cool, but then after turning off would get too hot in coach and AC would not come on unless I touched a button. I have been keeping unit plugged in and thermostat set to 88 just to keep it from getting too hot and humid inside coach with recent heat wave., and it had been acting fine as far as I know. Today I was packing for trip and noticed same thing with thermostat/ AC. I also noticed when I used water pump it ran unusual, kind of stop and start, with lights dimming in time with the way motor ran. Water was intermittently strong flow and weaker flow. I was hooked to shore power at my house. It also seemed like AC fan was not blowing quite as hard on high, but this could have been my imagination. I unplugged from shore power, hit battery disconnect, and voltage across two 6 cell house batteries was 13.54V. It seems like my problem is in thermostat, is this a twelve volt problem, esp with way lights dimmed with not so smooth water pump action? I'm planning on a trip this weekend and again in 2 weeks, nearest dealer 100 miles away to handle warranty issues. Any suggestions on what else I can test? I did put some screws in the wall for the remote for fan, on opposite side of wall from control panel, but well offset. I thought any wiring would probably be running fairly vertical, but could I have hit a wire? Don't know how this would affect water pump, but don't know where all the wires run in coach either. Thanks for any suggestions.

[La.Paul]

One other item, the day before I put in the A/B switch, I was in coach getting my sattelite signal refreshed from dish, and I had turned thermostat to 72, I don't remember it acting up then. I inadvertently left it set at that temp overnight, and we got down to 65. I read in the manual that temps this low could allow freezing of coils, so that is what I originally thought might be going on, so I turned AC off until I was packing today, but still acting up as described in prior post.

[TXiceman]

Getting down to 65 degF when it was set to 72 degF. It would run down to 72 and shut off. I would expect there may be a problem with the 'stat and it does not seem you did anything that would bother it. No knowing the brand/model, see it there is reset function on it. Should be an instruction sheet with the manuals.

Ken

[La.Paul]

It is a Coleman RV Comfort HP thermostat. Manual does not show a reset button. Does state there is a high pressure trip switch, that once thrown can only be reset by disconnecting AC power, which I did a couple of times.

[jerichorick]

The lights cycling has me wondering. Something is loading the system down rhythmically.

This is a far reach. Please check the connection tightness of your shore neutral, L1 and L2 if it is 50A service. Make certain that the plug blades are clean and lube them sparingly with some antiox grease as found in the electrical department at HD or Lowes.

Use great care when checking all the connections so no harm will come to you or your equipment. Shut everything down when you do this and make certain that ALL power is off. This includes the shore power, genset (open the breaker) and inverter. Open the transfer switch box and tighten all of the connections there.

As I have stated, this is a long shot but a good place to start.

Rick

[KIX]

Several things to check your house battery bank:
1. Turn battery charger off then disco house batt. bank positive cable. then check for continuity between positive CABLE and coach frame. This will tell you if you hit a positive 12v wire in the wall. Let's hope there is no continuity.
2. Disco shore power and check voltage at battery bank after about 1/2 hour. Should be close to 12.6. If below that suspect bad cell in battery. Check with hydrometer.
3. A hydrometer check of battery cells is a good thing to do anyway.......they're available at auto parts stores and inexpensive.
4. After reconnecting the battery bank, assuming you've not found an issue, turn off battery charger. Let it stand for about 30 minutes then check voltage while every light inside the moho is on. You should see at least 12+ vdc for several minutes without any rapid discharging. If you do see rapid discharge while under load then check with hydrometer.
Hope all this helps you find the problem

[La.Paul]

I took it to RV shop, and it turned out to be bad thermostat, they replaced it and all working well now. Thanks for all the input, it was a good learning experience.

[jerichorick]

How simple fixes can be. Glad you're back in service. Happy trails!