Why does my GMC Sierra not blow hot air?
Why does my GMC Sierra not blow hot air? Air won't blow out of the dash vents but the other modes work fine. Also occasionally blows hot air in A/C mode. Turning off the ignition and restarting corrects the heat issue. Driver's side heater/a-c works okay... passenger side only blows hot air, regardless of heat setting. What to do if your Chevy Silverado heater is not working? Turn the truck off and back on and sometimes this works. Blows heat out of driver side vents and drivers side center vent. Passenger side blows cold air for air conditioner setting. blowing...