2004 Gmc Sierra Turn Air Conditioner On Will Start Working Fine Sudden Blow Heat

2004 GMC SIERRA
147,000 MILES
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DARRYLRUSSELL
  • MEMBER
  • 1 POST
When I turn the air conditioner on it will start working fine then all of a sudden it will start to blow heat from the vents instead. then if you shut the truck off and start it again it will do the same thing again. sometimes it will blow heat out the drivers side and cold air out the passenger side?????
Jan 19, 2013 at 2:12 PM
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HMAC300
  • ✓ASE Certified Mechanic
  • 48,601 POSTS
  • ASE Certified Mechanic
first pull your hvac fuse for 60 seconds, that may straighten it out. then check your actuators under the dash on heater. thetemp one may be opening. when pullilng fuse after you reinstall it wait anotherminute for the control and actuator ro recalibrate.
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Jan 19, 2013 at 4:16 PM
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