F53 V8 Dash AC Problem

[Rickgreen61]

Good evening! My dash AC will work fine when I first start the coach and are idling or driving slow. When I get up to speed, the temperature gets very hot. I haven't checked the refrigerant levels yet and thought I would reach out first for suggestions. Thanks!

 

[Dan_Frisbie]

Check the ducting, too. Maybe a vent is open to outside air and it overpowers the a/c.

 

[BGMAC]

The ac/heat doors are electrically controlled vacuum operated. There are diagrams out there and easy to Google. It could be one of the controllers are opening at higher vacuum?