I have a 1998 Residency by Thor. The roof air forward unit runs 24/7 (in Arizona). It runs cold then warm, then cold then warm. Turning it off does not change anything. The aft unit runs (on then off ...
Ted, I had similar trouble last year when I showed up at Lake Havasu City, too early (Sept. 2012) the air wasn't working all that good. A local told me he thought (which he was right that) that there wasn't enough humidity in the air, at that time the humidity was only 8% as the winter season went on my air got better! I hope you have a similar problem that doesn't cost you $$$! Good Luck, Rooster