Q: Air conditioner blowing hot air. Then fan was running low then sped up to high.

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Hi there. This morning while driving to work, the air conditioner in my car was blowing hot air. Then as I neared work the fan suddenly dropped in speed then immediately sped up again. On my way home it was still blowing hot air. I left to go to auto zone, (who were no help at all) and while I was parked there after getting gas and turning off the car, all of a sudden the air started blowing cool; not cold, but cool. Of course. It's been doing this off and on very sporadically lately. I live in AZ and it is still in the high 90's. I appreciate any help you can give me. Thanks in advance.

My car has 79000 miles.
My car has an automatic transmission.

Hi there. It sounds like you have a low refrigerant charge; your AC system has a low charge. This is usually caused by a leak in the system. This low state of charge can cause insufficient cooling, thus the hot or cool air and not cold air is coming out of the vents. The fan running low then speeding up is normal as the AC system is being used; the high speed fan is what cools the refrigerant in the system. I believe you may have a leak in your AC system that needs to be checked. YourMechanic has several qualified technicians that can perform an AC system inspection to properly diagnose the concern at the comfort of your home or office.

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