I have a 2000 chev Tahoe. My problem is my heater stopped blowing hot air, just cold now, there is no anti freeze leak or no "sweet" smell of antifreze inside the truck. This wouldnt be a problem in the lower 48 but as Im in AK and its cold this is a big prob. I replaced the thermostat, and flushed the cooling system in hopes this would be the fix. I was wrong. I called a dealer and was told it could be the temp control door. I have no idea what that is or where to locate it. Could anyone please help.