Q: My a/c intermittently blows warm and cold air.

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My a/c works fine some of the time and then it starts blowing warm air and then back to cold. The compressor has been tested and is fine and I have had it charged. I live in Phoenix and use my air year round and really need to figure this out. Help!!

My car has 174000 miles.
My car has an automatic transmission.

It is possible that your blend door actuator could be failing and going back to the default position. Many vehicles will default the blend door to heat mode. When the blend door actuator fails, it will automatically revert the door back to this default setting.

I would recommend having your blend door actuator tested using the manufacturer’s recommended procedure by a qualified technician such as one from YourMechanic. One of our mobile technicians will be able to come to your home or office diagnose the issue with your AC and help you make the necessary repairs.

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