I know this sounds silly, but have you checked the switch on the thermostat to make sure it is on "cool" setting. I notice that sometimes the switch get stuck in neutral as it were. If the compressor is kicking on( lower the temp switch its lowest setting) and you are still not getting cold air, you may have a leak and lost your freon. Well, its not called freon anymore but it is environmentally safe chemicals. You can have the system checked for leaks and recharged. On my last motorhome I had my ac guy that works on my ac system at the office come to my house and work on the mh ac system. It worked great after that and I never had to move my MH to get the work done.