2014 f-53

[jdpm]

2015 Vista on '14 chassis. The dash hvac functions as it should from the off position to the left, or counter clockwise. From the 12 o clock position to the right, it doesn't change to defrost or heat. The a/c compressor will turn off but the air flow does not change from the dash vents to the defrost or heater vents. Thanks!

[HarryStone]

The Ford manual is worthless for this because that part of the HVAC is provided by the coach manufacturer. I'd start by checking the vacuum lines. There should be a vacuum bottle under the front of the rig, make sure the vacuum line didn't come loose, then start from the top of the engine, you will probably have to remove the engine cover to gain access, check all the vacuum lines for security and not chewed.

[Tallcamper]

You will find all the manuals and repair info here
https://www.proairllc.com/design-eng...empcon-guides/