ac on when defrosters are on how to turn off | Ford Escort Owners Association (FEOA)
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ac on when defrosters are on how to turn off

Discussion in 'HVAC' started by sundance561, Nov 19, 2017.

  1. sundance561

    sundance561 2B gravel

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    my daughters 97 escort's defrosters when on the ac is also on is there anyway to disable the ac when on
  2. denisond3

    denisond3 Moderator Staff Member

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    With my 2nd gens, the a.c. would be on when in defrost - but not if I had the fan control set to zero. Im not sure the 3rd gens are wired that way.
    Basically the heater and a.c. controls are set up on purpose, to have the a.c. running when the lever is in the defrost position and you have the fan control on any position except "off". The reason is to give the a.c. compressor some use during the months of the year when you wont be using the a.c. to cool the interior. This gets oil lubing the shaft seal inside the compressor, and extends its life dramatically' i.e. its done on purpose. Most folks arent even aware the a.c. works when you are using the defrost function.
    If you went 6 months without using the a.c. compressor, it would likely start to leak after 2 or 3 years - instead of maybe lasting for 8 to 10 years.
    To defeat it I think you would need to add a switch in the line going to the compressor.
    zzyzzx likes this.
  3. Pizzaman5000

    Pizzaman5000 FEOA Donator

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    I wanted to add that A/C helps the car defrost the INSIDE. The outside, not so much. If Ice is your issue, ac will hurt, but if the interior is moist, ac will help you. You just need to move the temperature lever more towards full hot.

    is your A/C really good, or your heat really bad? Ha ha

    Maybe a coolant flush is what's really best right now. I avoid the defrost and a/c issue in most cars by moving the lever to feet only, and inch it over until I get some airflow on he windshield, and more on my feet. Or vice versa, whichever is a good blend with no a/c.

    I smoke so biasing towards the floor with a high fan speed ventilates the car best as far as smoke odor is concerned. The draft blows smoke everywhere, instead of out the slightly cracked window. But if you have moisture, your shoes and carpet may be wet, and contributing most to humidity. You can get away with some defrost, good dehumidification, and no A/C this way.

    the puddle that forms under cars with the a/c running is a testament to how much moisture the a/c removes.
    Last edited: Nov 20, 2017
    4cylinder and denisond3 like this.
  4. marclar

    marclar Moderator Staff Member

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    you don't want to disable the ac during defrost. it removes the moisture from the cabin. all modern cars do this by default.
    4cylinder likes this.
  5. denisond3

    denisond3 Moderator Staff Member

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    Not only by default, but I think its by US DOT requirement.
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  6. zzyzzx

    zzyzzx FEOA Member

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    Your A/C works in your Escort?
  7. denisond3

    denisond3 Moderator Staff Member

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    Not anymore.
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