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Air conditioner starts from defrost then switches to dash vents

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Old 06-13-2012, 11:24 AM
rbl_at_home's Avatar
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Post Air conditioner starts from defrost then switches to dash vents

My Mercury 2004 GS with ETC Air conditioning starts from defrost then switches to dash vents.

Is the a way to reset the ETC to factory defaults?

Thanks in Advance
Russ
 
  #2  
Old 06-13-2012, 03:49 PM
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Usually when a HVAC system goes to defrost there is a lack of vacuum to operate the right mode. Defrost is the default when the vacuum source is gone. The blend doors, and mode doors are operated by engine vacuum. Start with checking the feed from the engine to the HVAC box. Then pull the Climate control head and ck for vacuum there. The head could also be bad. Not sending the vacuum to the right place quick enough.
 
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Old 06-15-2012, 02:44 PM
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Originally Posted by 91GrandMarquisGT
Usually when a HVAC system goes to defrost there is a lack of vacuum to operate the right mode. Defrost is the default when the vacuum source is gone. The blend doors, and mode doors are operated by engine vacuum. Start with checking the feed from the engine to the HVAC box. Then pull the Climate control head and ck for vacuum there. The head could also be bad. Not sending the vacuum to the right place quick enough.
I do not believe it is the Vacuum. All of the other settings, except vent work OK
 
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Old 06-27-2012, 01:10 PM
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For safety reasons the default position is defrost on. If/when the system operates correctly it changes to a/c. If it stays on defrost, then you have an issue.
 
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Old 07-25-2012, 02:23 AM
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Then pull the Climate control head and ck for vacuum there. The head could also be bad. Not sending the vacuum to the right place quick enough.
 
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Old 08-23-2012, 03:13 AM
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Start with checking the feed from the engine to the HVAC box. Then pull the Climate control head and ck for vacuum there. The head could also be bad. Not sending the vacuum to the right place quick enough.





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