[Clint]

Maybe the sensor needs a few seconds to sense the temperature to then actuate the door. I never use the auto settings.

Clint

 

[Clint]

Do any of you ever for whatever reason sit in the truck for a few minutes after turning the engine off? You all of a sudden hear servos moving without touching anything maybe they go back to a neutral position and that is one where the heater core is exposed to the air flow. Once the system is energized it goes back to the A/C on setting.

Clint