Heater system blowing out cold air

2003 GMC SAFARI
194,104 MILES
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ROCC SAUL
  • MEMBER
  • 1 POST
heater system seems to be blowing out cold air. I replaced the thermostat and it is still blowing out cold air. Can I myself an unlicensed mechanic fix this problem myself?
Jan 13, 2017 at 7:07 PM
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WRENCHTECH
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 20,761 POSTS
With the engine at full operating temperature, locate the two heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If they are both hot, the heat in that vehicle is controlled by a blend door that regulates heated air flow. it is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.
Jan 13, 2017 at 7:30 PM
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