Air conditioning won't come on

We started up the motorhome this afternoon to let it run for a while. Since we're having a hot spell here we decided to run the air conditioning. It's a 2002 that we bought used in 2007 and can't remember if we checked it during the walk-through. We've never had to use the air since buying the rig and we couldn't get it to come on now. We set the thermostat for cool, set the temp down around 60, and the fan on high. The LP was on and the generator was running. My DH said the fuse in the thermostat was fine (can you tell by just looking?). We tested the furnace and it came on just fine (I guess that indicates the fuse was good). What should we check now? We're pretty much newbies when it comes to RVing. Thanks for any help you give me.
Re: Air conditioning won't come on

Well, I am best on trailers, but I can tell you that LP has nothing to do with your AC. Your AC needs electricity. You said you set the fan on High, but did not say if it ran.

Now, if you were relying on the Generator for electricity, was anything else working on electric? If not, your AC will not either. If nothing else was working, your problem could be with your generator or transfer switch. Try using your electric cord and see if the AC works.

You also need good batteries for the AC to work, the control board is controlled by 12 volts. Since the furnace worked, that is probably not your problem. Just a little information.

Let us know what you find.
Re: Air conditioning won't come on

Thank you for trying to help, Ken. I appreciate all the good information you so willingly give on this site. You're very knowledgeable and helpful. I don't post much at all but I do read the posts often.

While I was reading your reply to my husband it suddenly dawned on him what the problem was ~ he hadn't plugged the generator in. We rushed out, plugged it in and the air came right on. We don't use the MH very often so every time we do we fumble around trying to remember what to do. It's like we never get out of the beginner stage.

Anyway, thanks again.


DL Rupper

Senior Member
Re: Air conditioning won't come on

Try making a check list. That will put you at the intermediate stage. We still use one after 13 years full-timing.
Re: Air conditioning won't come on

We have a we need to actually CHECK it! Thanks for the reminder, DL. I'd love to upgrade to intermediate, LOL.

SEMPER FI back from the wife of a Vietnam Marine Vet.

Re: Air conditioning won't come on

Hey Pat...stick with us and we'll have you at intermediate in know time...or least you'll think you're intermediate. Shoot, sometimes I get so far from home I began to think I'm near expert...then I get back home and all is well with the world.
Re: Air conditioning won't come on

I'm in northeastern Ohio so, I don't even think about AC until mid June!
The check list is a good idea, I always take a peak at mine before leaving, just to make sure I didn't forget to do anything.