[Keeler]

05 2500HD 6.0. Randomly just the driver side will switch to heat and will not go back to cool until you turn the truck off and restart it. Passenger side stays nice and cold. Regular style cluster, not the auto. Anyone have a clue what's going on

 

[ItsSabby]

Probably the drivers blend door actuator. It's the one located in the center of the dash by the floor. You can set it to cool and disconnect the connector so it stays on cool. And reconnect if when you need to go back to heat. Or you can replace it.