AC problems

[bmnelson23]

I have a 99 ford expedition, 5.4 4x4. AC works fine unless the car sits in the sun parked and turned off for a few hours. If it has been in the sun, upon starting the car, the AC and the blower motor do not turn on. After running the car for 10-20 minutes, the AC will kick on perfectly. This happens in the summer and the winter. The Heater will always turn on regardless of being in the sun or not during the summer or the winter but the AC will not turn on in the summer or winter if it has sat not running in the sun for a few hours. If the car is parked in the garage, regardless of summer or winter, the AC kicks on every time. Any help is greatly appreciated. Would a faulty resistor motor behave like this if it got too hot? Is there a sensor somewhere that is causing the AC and blower motor to not turn on? Help.

 

[99WhiteC5Coupe]

I have a 99 ford expedition, 5.4 4x4. AC works fine unless the car sits in the sun parked and turned off for a few hours. If it has been in the sun, upon starting the car, the AC and the blower motor do not turn on. After running the car for 10-20 minutes, the AC will kick on perfectly. This happens in the summer and the winter. The Heater will always turn on regardless of being in the sun or not during the summer or the winter but the AC will not turn on in the summer or winter if it has sat not running in the sun for a few hours. If the car is parked in the garage, regardless of summer or winter, the AC kicks on every time. Any help is greatly appreciated. Would a faulty resistor motor behave like this if it got too hot? Is there a sensor somewhere that is causing the AC and blower motor to not turn on? Help.

Does the a/c system compressor not run AND the HVAC blower motor not run when this happens, or only the blower motor?

Do you have rear air? Does the rear blower motor run when this happens?

A defective blower motor speed control (resistor unit) usually only affects the front HVAC blower motor.

Have you examined the wiring connector at the blower resistor and also at the front HVAC fan motor?

These links may help you:

https://static.nhtsa.gov/odi/tsbs/2019/MC-10163573-0001.pdf

And

How To Replace Blower Motor Wiring Harness 2007-2017 Ford Expedition

Shop for New Auto Parts at 1AAuto.com https://trq.video/c-157-ahThe heat and air condition fan is controlled by a separate module, called the blower motor re...

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