I have been reading and searching and i dont know which to try first. I took off the cover and i can see the blend door is working fine so its not broke like the older commom problems most have, its fine. But i can watch the blend door motor turn from hot to cold back and forth for no reason when i have it set on cold...is this a blend door motor problem or a switch control potentiometer issue yall think, anyway i can test them to make sure...Some days it will work fine, then on some it will jsut cycle between hot and cold over and over....thanks in advance for the help