Heater on my 01 GMC Sierra doesnt fully work
Last summer, on cool mornings, I noticed that the heater didnt start blowing hot air once up to temp. Later in the day when it was hot out, I went to turn the temp to cool, it kept blowing hot air for a long time until finally cooling down like the control wasnt working. Now when I need heat, its -7 below today, I find its blowing warm air when its up to temp. It gets alittle warmer when i am driving. Any possibility its the temp. control rheostat on dash panel?