Mechanics

FRONT A/C WORKS OFF AND ON

2000 Ford Expedition • 120,000 miles

My rear a/c works perfectly. My front a/c will work all day sometimes and other times not at all. Some days it goes back and forth from hot to cold. I've checked the pressure and refrigerant levels and they are normal.

I've read posts online and seen everything from blend doors and actuator motors to evaporators and thermostatic switches, but, none of the symptoms for those items quite fit my situation.

Any suggestions?

Thanks.
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Bunyon2
June 7, 2012.




Is HVAC manual or Automatic? If automatic a scan tool can be used to perform self diagnostics. This will test each sensor and actuator to find problem

Docfixit
Jun 7, 2012.
It's manual. Does the fact that the problem is intermittent sound like a sensor or actuator issue?

Tiny
Bunyon2
Jun 7, 2012.
Yes blend door actuator loacated behind center dash controled by potentometer. Find actuator operate temp control motor should respond by moving from cool to hot. Being intermittent is going to make repair difficult

Docfixit
Jun 8, 2012.
The next time it goes warm, leave the front on and the rear off and feel the temp of the line coming out of the evap to the accumulator and see if it is cold. If so, you have a blend door or blend door control issue.
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Wrenchtech
Jun 8, 2012.

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