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Q: My ac only blows through defrost vents

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Okay well my ac currently only blow through my defrost vents, it was freezing cold for awhile but now it's hot, I put ac coolant in the truck and I heard a hissing coming from in front of the radiator, making me lean towards a bad ac condenser but would a leak in the condenser cause my ac to blow through my defrost vents only? Because I was told it's a vacuum leak but that's the only leak iv found and it wasn't hissing or anything until I recharged my ac (which was completely empty)

My car has 252000 miles.

A: Hello. From the symptoms you've describ...

Hello. From the symptoms you've described it would appear to me that the vehicle may have more than one problem.

The hissing coming from the AC condenser may be a sign of a potential leak, especially if it occurred after you added refrigerant. I'd check to make sure the refrigerant is at the correct level and that there are no leaks present, as any AC refrigerant leaks can cause problems with the functionality of the AC system.

In regards to the air only blowing from your defroster vents, I would check the vehicle's AC mode switches, and blend door actuator to make sure they are operating soundly. The AC switch controls the modes that the AC blows through, so any issue with the switch may cause problems with what vents the system can operate from.

The blend door actuator is the component that mechanically selects what vents the AC system works through, and if it fails or gets stuck, can produce the symptoms you are experiencing.

If you need assistance with these checks, see the help from a certified mechanic who can diagnose your AC issue firsthand and fix it accordingly.

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