2007 Ram 1500. I installed heater treater doors along with new evaporator and heater core a couple years ago. It was working flawlessly until now. Recently I’ve noticed an odd problem with the temperature control. If it is turned to full heat, when I turn it down about 1/2 to 3/4 of the way, it continues to blow hot air at the foot well and luke warm on the face. It will continue to do this until I turn the temperature to full cold. I also replaced the actuator for the temperature door, it didn’t solve the issue. Any suggestions?

So, I removed the dash and checked all the blend doors. They appeared to be all good, but heater treater sent me new doors, so I replaced them anyway. The problems persists though. If I go from heat to cool, not full cold, the vent temperature is not as cold as it should be unless I turn to to full cold and then gradually increase it. Anyone have any other suggestions?