Terryallan wrote:
Often, Especially on Dodge products. the doors will go the the defrost default position when you are towing, especially while pulling a hill. Why? Hard pulling causes low vacume pressure, and when the system loses vacume. It goes to the default Defrost position. It goes there, so IOF you lose all vacume. At least the defroster will work.
The climate controls on a Ram diesel are not vacuum actuated, at least 2004 MY and later. The blend doors are (about 4 total) operated by 12v motors/servos attached to plastic shafts on the doors. The shafts are notorious for breaking. To the OP: While blend door problems are a possibility, I would also consider The climate control module in the dash; in a 10 year old truck a problem with that module (electric/electronic) wouldn't be surprising.
