Skip the auto shop - Our mechanics make house calls

Q: AC Blowing from vents and defrost

asked by on

When I have the control knob for AC on front vents it blows out of all the vents including defrost. If I have the knob set to defrost the air only comes out of the defrost vents. What could be causing this issue?

My car has 70150 miles.
My car has an automatic transmission.

A: The air conditioner blend door is controlle...

The air conditioner blend door is controlled by an electronic actuator and if the door is not in set position then you may have a defective actuator and need to replace it. The door operation should be in the manual mode to make sure the actuator is defective or there is a blend door stuck from something getting down in vent door. Sometimes a pen, paper clip, or pencil can fall in the defroster vent and can lodge in the door and not let it seal. If this is the case, then the evaporator case may need removed to get out the item out of the case door. I would have a professional scope out your AC system firsthand and determine what fixes will help.

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・Save up to 30%

Get a quote

What others are asking

Q: Fan wont blow out top vents for defrost.

Hi there. Check the blend doors to the vents and see if they move when the switch is turned. If they do not move, then check for a vacuum hose to the blend door actuator. If there is no vacuum...

Q: Car overheats when running A/C

Your Jeep has a mechanical cooling fan and an electric cooling fan. The electric one is hidden in the fan shroud. Its main purpose is to turn on when the A/C is on. It is a quiet fan, so you...

Q: Hi Shaun! Can you help me determine whether my mechanic was being legit re: my AC issue?

Hello, thanks for writing in about your Kia Rondo. Unfortunately we can't confirm whether your mechanic is being legit because we don't know the complete conversation between you and the mechanic. Shops have their own prices for their services. You...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...