2006 travel supreme

Seems like you lost vacuum to the heater-A/C controls
Check all the small vacuum tubing under the front hatch and vacuum canister and under the dash between a/c controls and the duct work and blower
Your RV might use engine vacuum, or it might have a small vacuum pump, really small like 4 inches square or smaller , 12v and under the dash

Or it could be the mixer control switch or box.

Or it could be you just need it re-charged. Go to an A/C shop for advice and repairs. Most DIY don't have the necessary equipment to test/fix dash airs that work but don't blow cold.....Dennis

Sounds to me like your hot water valve is not stopping the flow of hot
water through the heater core . The hot will easily over power your A/C .
Usually when this is the problem it will cool at first before the engine
warms up . You also should feel more heat on one side of the valve if it
working . My valve is on the firewall where the heater hoses enter the HVAC .

Thanks fot the ideas. I will be checking this as much as i can. In storage for now.