Skip the auto shop - Our mechanics make house calls

Q: My ac only blows through defrost vents

asked by on

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.

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My 1997 Dodge Dakota is leaking oil from the oil filter housing

Hello. I would have to see the vehicle to know for sure but it sounds like you have a leak from the oil filter housing. Most of the time it leaks here when the o-rings wear out though it is...

Q: my 2005 dodge dakota makes a clinking sound when i hit bumps or push down on some of the fender wells, what would your guess be? A

Hi there. In most cases, when you hear creaking sounds when you drive or press down on the fenders, it's caused by worn out struts, shocks or bushings that are worn out. I wouldn't suspect this would be a mechanical...

Q: my clutch went out on my truck? i got the clutch fixed but now the truck will not start. what do you think is wrong??

Hello there, A few different things can cause the car to not start. The most common causes for no start is the battery, starter, neutral safety switch or the fuel pump. Given that it started before you performed repairs it...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...