I have a 2016 Forest River Rockwood 5th wheel with a Coleman Mach air conditioner in the kitchen/living area. I've seen intermittent operation that concerns me. The other day we returned from dry camping/boondocking. It was about 90 degrees outside and sunny. When we returned home, we parked the RV in the driveway and hooked it up to 110 vac, 15 amp service using the 50 amp cable and a couple pig tails to get it to the right connector to plug in the outlet. We then turned on the air conditioner to cool things down while we unload and clean the RV. Everything seemed to work fine. We left the air on all night so that as it heated up the next day it would keep the temp around 70. I went out and noticed it was hot out but the RV wasn't cooling. It sounded like it was running but sounded different. The internal temp was around 88 degrees and the outside temp was 92. I turned the air conditioner off and opened windows and ceiling vents to try and get air flow through the camper. We live in a dry climate and air movement and shade really cools things down. Later in the day, I tested the air conditioner and it seems to blow cool air again. The outside temp was 85 degrees and the inside temp eventually reached temps below 70. I've had this happen before. I took it into Camping World to have it checked. They said everything was fine. They told me they look for a temperature differential of about 20 degrees to know if it's working. I can't seem to get it to fail while the mechanic is checking it. Any thoughts on the unusual behavior?

Make and model of thermostat?Possible that it froze up.Could be low on refrigerant.

I'd also guess that it froze up. You could start by making sure the filter is clean. Also, make sure the fan is on "High".

Sounds like ice up to me. Were you running it on low fan? If so, in high humidity conditions, the fins up top can ice up and the thing will not blow cold air. Turning it off will let the ice melt and it will work fine again. The solution, in most cases, is to make sure the fins are not clogged up and to run the air conditioner on high fan all the time.Barney

It sounds like the fan was running and blowing ambient air. I have Coleman Mach 15's on my coach and more than once I have has the same thing happen. It seems to happen when very hot outside (110+), dry, and the coach is hot inside (90+). I have full air flow out the vents so it is not icing up. If I turn off the unit for a minute then back on it will works fine. I think the compressor is overheating and shuts off. It won't come back on without shutting it off and back on. I also notice that if I do not allow the inside temp to get above 85 of so it will stay running even at 115 outside.In your case the 15amp extension cord could be overloaded causing a low voltage issue too.

Using adapter plugs especially two of them can cause a problem as well if there is dirty contacts. If the adapter plugs are warm or hot they don't have good contacts.

Don't understand my air conditioner | Good Sam Community

2012Coleman
Explorer II
Jul 25, 2017
OP wrote:
When we returned home, we parked the RV in the driveway and hooked it up to 110 vac, 15 amp service using the 50 amp cable and a couple pig tails to get it to the right connector to plug in the outlet.
Maybe I'm misinformed, but I thought that you could not run the AC on household current. I'm not an expert in electricity, but I'm guessing CW plugged into a 30 amp plug. I just had one wired for me at the new house. It's nice having a cool TT to load/unload/do repairs on.
colliehauler
Explorer III
Jul 25, 2017
Using adapter plugs especially two of them can cause a problem as well if there is dirty contacts. If the adapter plugs are warm or hot they don't have good contacts.
dkreuzen
Explorer
Jul 25, 2017
It sounds like the fan was running and blowing ambient air. I have Coleman Mach 15's on my coach and more than once I have has the same thing happen. It seems to happen when very hot outside (110+), dry, and the coach is hot inside (90+). I have full air flow out the vents so it is not icing up. If I turn off the unit for a minute then back on it will works fine. I think the compressor is overheating and shuts off. It won't come back on without shutting it off and back on. I also notice that if I do not allow the inside temp to get above 85 of so it will stay running even at 115 outside.
In your case the 15amp extension cord could be overloaded causing a low voltage issue too.
BarneyS
Explorer III
Jul 25, 2017
Sounds like ice up to me. Were you running it on low fan? If so, in high humidity conditions, the fins up top can ice up and the thing will not blow cold air. Turning it off will let the ice melt and it will work fine again. The solution, in most cases, is to make sure the fins are not clogged up and to run the air conditioner on high fan all the time.
Barney
ScottG
Nomad
Jul 25, 2017
I'd also guess that it froze up. You could start by making sure the filter is clean. Also, make sure the fan is on "High".
enblethen
Nomad
Jul 25, 2017
Make and model of thermostat?
Possible that it froze up.
Could be low on refrigerant.

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