A/C Struggling to Stay On

[Gramama]

I’m new to full time rv’ing and am using my roof a/c for the first time. Yesterday it ran ok, although I didn’t think it was terribly efficient. Today I turned on the LR unit and it ran a few minutes before it started randomly turning on and off. It wasn’t because the set temperature was reached. Its obvious that it has some sort of problem. I turned it off as soon as I realized it was having issues so as to not cause further damage. I’m wondering if anyone has an idea of what the problem might be or can tell me if there’s something I can check on my own before calling a repairman. Its a Dometic but I don’t know the model or even where to find that information. The 5th wheel is a 2013 M-3585RL Bighorn. I’m also considering just getting some type of room a/c. Some are reasonably priced but I haven’t gotten as far as reading any reviews. Does anyone have a recommendation? Thanks for your help.

 

[sengli]

Could be a lot of things causing your issues, but are you plugged into 30 or 50 amp AC service? You can run one of the AC units at a time if only on 30 amp service. Could be you have some nests, or other debris in the unit on the roof?

 

[Gramama]

I’m on 50 amps. Checking the roof units is a great idea. I’ll do that first, although I did try it again later today and it stayed on even though it seemed to skip a few beats. I might just be paranoid. Just about everything that could’ve gone wrong since I bought the rig, has. I might just be looking for trouble that isn’t there. Anyway, thanks for your reply.

 

[Roller4tan]

Still a good idea to get up on the roof and take the covers off to check for debris in the coils, blow it out with air or water from the fan side.

 

[Gramama]

I’m putting my son right on it. Thanks for the advice.

 

[Hollandt]

I’m new to full time rv’ing and am using my roof a/c for the first time. Yesterday it ran ok, although I didn’t think it was terribly efficient. Today I turned on the LR unit and it ran a few minutes before it started randomly turning on and off. It wasn’t because the set temperature was reached. Its obvious that it has some sort of problem. I turned it off as soon as I realized it was having issues so as to not cause further damage. I’m wondering if anyone has an idea of what the problem might be or can tell me if there’s something I can check on my own before calling a repairman. Its a Dometic but I don’t know the model or even where to find that information. The 5th wheel is a 2013 M-3585RL Bighorn. I’m also considering just getting some type of room a/c. Some are reasonably priced but I haven’t gotten as far as reading any reviews. Does anyone have a recommendation? Thanks for your help.

It could be several problems but if you have the fan in automatic setting, the high speed will run when the setpoint is much lower than the actual temp(maybe >4 degrees). As actual temp get closer to setpoint(maybe 2 to 3 degrees above)it will switch to low speed. During this switch over the fan will completely stop for several seconds. The compressor continues to run. I have noticed mine switching between low to high and high to low repeatedly sometimes if the load and the temp inside is within this switch over range to the setpoint.