Report "The 2006 Hyndia tucson limited has 95,000 miles on it and the interior heat does not mix cold air. Then vehicle temp is normal The temp gage shows that temperature as normal. Engine coolant storage resouvior is cold. When turning interior heat up on the digital control the plowed fan will increase to raise temperature. As to erasure is met the plowed fans drops to lowest speed but hot air continues to come out of the vents. I assume the cold air damper isn't working. Would that be a vacuum issue? Or could that be a sensor issue. ? I don't think so. Is the cold air mixing damper vacuum operated or does that have a electric motor ? The interior over heats because the air coming out the vents doesn't adjust to allow cold air"