My 2000 Durango heater & a/c are a little screwed up. My explaination may have you wondering about my mental status, but here goes.
The air is always "hot", regardless of the switch locations, BUT, if I lock up the brakes and emergency stop, the A/C will begin working......... then if you juice the gas, even a little, the hot air starts blowing again.
There is no temp control, the air is as hot as it will get, unless of course you pull the emergency stop trick again.
Expansion Valve ??? Any advice would be greatly appreciated.