Question about 1998 GMC Sonoma

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Heater does not work

The heater does not blow hot air.  Occasionally it might blow lukewarm but never hot.  The air direction switch works fine as does the fan.  Just no heat.

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  • 2 more comments 
  • Anonymous Mar 12, 2014

    heater worka just wont blow air

  • Anonymous Mar 12, 2014

    heater fan will not blow

  • Anonymous Mar 12, 2014

    the heater turns on and works but will not blow any air when you turn the fan on and up

  • Anonymous Mar 31, 2014

    Heater blows 32c hot or just cold

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  • GMC Master
  • 6,982 Answers

Check blend door motor for proper operation (vacuum operated) if necessary, detach arm from heater box and move by hand. If you have heat then, change motor! You are reaching operating temp for engine, right? If not, thermostat is stuck open... Change.

Posted on Dec 22, 2008

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