Heater blows hot at idle and cold while driving

Tiny
CHEVYBOY317
  • MEMBER
  • 1990 CHEVROLET 1500
  • 80,000 MILES
When I idle my heater is hot. When I am driving down the road it blows cold. Any suggestions? New thermostat. Will a bad clutch fan make it do that?
Saturday, November 25th, 2017 AT 5:44 PM

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