HEATER WONT WORK

  • Tiny
  • muttnru
  • 2001 Mercury Mountaineer
  • V8
  • 2WD
  • automatic
  • 121,091 miles

The air conditioner works all switches work, the the heater will not come on.

Thursday, December 23rd, 2010 AT 6:01 PM

3 Answers

  • Tiny
  • Wrenchtech
  • Expert
  • 19,814 posts

Do you mean the temp of the air is not hot enough or that the blower is not working?

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Thursday, December 23rd, 2010 AT 6:19 PM
  • Tiny
  • muttnru
  • Member

Blower works but it will not get hot. Thermastate is good. All valves are working to heater core. It will not change from air to heat.

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Thursday, December 23rd, 2010 AT 6:24 PM
  • Tiny
  • Wrenchtech
  • Expert
  • 19,814 posts

With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both too hot to hold. If they are.

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.

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Thursday, December 23rd, 2010 AT 6:30 PM

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