Community Forums

Sang Froid · 02-06-2025, 10:38 AM

I went to turn on my AC (it worked fine when last used about six weeks ago during a short hot spell while in AZ) and it didn't come on. I checked the breaker box and it hadn't flipped but when I turned it off and back on I could hear a slight change in the generator. I turned on the heater and the fan from the same thermostat and neither worked also.
I therefore assumed that the thermostat was at fault but wanted to check with the smart folks here to see if there might be another reason. If not, can I get some suggestions for a reasonably inexpensive replacement. Mine is a Coleman-Mach that came with my 2003 Thor Hurricane.

Kahoona · 02-06-2025, 12:46 PM

Lets try the most likely thing. You don't mention what kind of generator you have but the likely ones for that age have a breaker in plain sight on the front. These can often pop without the generator shutting off so it seems as if you should have power. Try that then look and see if the light is on on your microwave. If it is out that the power is not coming from the generator. Check those things. Tell us what generator you have. The Onan 4000k won't run for more than a few minutes so you are capable of producing power up its own breaker so the genny is probably fine.

Some other things that have caused that on our 2001 coachmen are a broken breaker (get a multimeter and carefully check for 120 at the output end of your RV in the fuse box. If you have 120v there then it could be the thermostat or the AC. Let us know.

scenic route · 02-06-2025, 03:50 PM

Might try a CCC reset. Simultaneously press and hold the "MODE" and "ZONE" buttons while ensuring the thermostat is in the "OFF" mode; the LCD will display "IniT" indicating a system reset is occurring; release the buttons once the reset is complete and then use the ON/OFF button to exit setup mode.

I usually had to do this at least once a season...now we have two new 15k
heat pump A/Cs and a new thermostat that can actually be read.

kwftlaud · 02-11-2025, 07:46 PM

mine did something like this when I first got it
I opened it up and gave the fan a push and it started to turn, and cool.
When I got home I replaced all the capacitors which I bought from Amazon for $30. Has worked fine for 3 years. My coleman is a heat pump too.

Sang Froid · 02-12-2025, 08:16 AM

I responded to all of you last week! When I didn't get a response I checked and saw my response wasn't posted!

Kahoona, I have a 4000W cummins onan newly installed in 9/19 and has no breaker in front or anywhere else I could see. I run my kitchen appliances off of it (the microwave lights up) as well as the refrigerator. Also, a couple of heaters when needed, so I don't think the get would be the problem. Breaker panel is OK.

Scenic Route, Not sure what a CCC reset is. However, the thermostat is not digital.

Do any of you know or recommend a replacement? I looked for a wiring schematic but couldn't find one that showed a picture of thermostat wiring.

Sang Froid · 03-25-2025, 07:18 PM

This is probably a stupid question. It has been cool since I last responded on here but now the heat is here. It will be another week or so before my thermostat arrives (I'm boodocking). Can I connect the red and yellow wires to run the AC or would I also have to connect the fan (Brown) and ground (green) wires somehow? I'm guessing not but in the off chance I could do a temporary wiring without blowing up my AC I thought I'd ask.