Hot Air from A/C vents

[billk42]

??? OK ANother question,  When we use the A/C system (Engine Compartment, not Coach), and we are parked in the drive, it cools fine, blows cold air etc. I even recharged it to make sure everything was OK.  However, when we drive, almsot as soon as we start off, the air turns HOT, no matter where we set the temp control, just warm/hot air.
I know it CAN cool, because as I said, I recharged it etc., and it ran cool as long I wasn't driving.
Anyone have this issue? any idea what I can do next?

 

[King]

Two possibilities I can think of...    The temperature control for the heater could be defective.  As the engine heats up. a full on heater control will over ride the AC.    Or the charge in the system may be too great.  In order to work properly, the suction side pressure has to be low enough to evaporate the liquid refrigerant.  If there is too much in the system, it will gradually stop working as the overall system heats up and the refrigerant expands.
Art

 

[Alaskansnowbirds]

Sounds like a bad heater control or bad vacuum. Most controls are vacuum controlled. When you are sitting still and the engine is running you have plenty of vacuum to keep the valve in the cooling position. When you start to drive the vacuum drops and the valve goes to it's default position which I think is full heat. The first thing I would check is the vacuum line to the control valve.