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. Blower works but it will not get hot. Thermostat 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 6:01 PM

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Tiny
WRENCHTECH
  • EXPERT
  • 20,941 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
Tiny
ALEX PETERSEN
  • MEMBER

The heater cores were common on the Mountaineer. Mine was a pain to do- it took 11 hours(also I don't have much mechanical experience)

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Wednesday, December 6th, 2017 AT 5:46 AM
Tiny
2CARPROS KEN
  • ADMIN
  • 12,141 POSTS

Great addition to this thread! Please feel free to help out whenever you are on the site :)

This guide can help others that visit this page.

https://www.2carpros.com/articles/car-heater-not-working

and

https://www.2carpros.com/articles/replace-blend-door-motor

Cheers, Ken

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Friday, December 8th, 2017 AT 5:37 PM

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