1996 Ford Taurus A/C stays on

REGBAKER

MEMBER
1996 FORD TAURUS
6 CYL
FWD
AUTOMATIC
28,000 MILES

I noticed the heater does not get very hot. Examination showed the heater core is clean. Realized that the a/c is on whenever the HVAC system is on. The temp selector provides air between ice cold and a little bit warm. It is the same whether the mode is a/c, heat, or vent. It was suggested that the a/c damper door may be the problem, but I'm thinking electrical, since I would think the a/c compressor should not run in vent or heat.

5 Replies

BILLYMAC

MECHANIC
2,204 POSTS

Yes you would think heat means no air. However a room full of ford engineers deceided that it would be nice to design a blended air. They named it blend air system.

Their theory was to mix ice cold air with warm air to reach the desired temp the operator wanted a couple mins faster. Bad idea.

So now back to the blend air door yes it can be open and yes usually this is an electrical prob the elec door operator has failed so up under the dash on the heater box you will find this part actuate your heater controls and watch it see if it is only partially closed.

As far as the a/c I unplug mine every winter no prob

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Tuesday, September 28th, 2010 AT 7:50 PM

REGBAKER

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3 POSTS

I have a full range of temp settings from ice cold to just luke warm. Does that indicate the blend door is binding or the motor stopping before it gets fully closed?

Regarding a/c running all the time, does that include when system is on vent? Is the a/c compressor running in case one decides to turn it on and get quick results?

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Tuesday, September 28th, 2010 AT 8:19 PM

BILLYMAC

MECHANIC
2,204 POSTS

Yes this normally means the door is not closeing all the way

yes the compressor will run on heat defroster or a/c
this is a common prob with all heating systems. As long as your temp is normal heater hoses are hot then the blend door has to be stuck

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Tuesday, September 28th, 2010 AT 8:30 PM

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Mine also runs on vent. That is not correct, is it? When HVAC system is off, both heater hoses are very hot - showing circulation through the core. When on, one heater hose is very cool.

I've determined that the a/c is cooling the heater core.

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Tuesday, September 28th, 2010 AT 8:38 PM