Skip the auto shop - Our mechanics make house calls

Q: A/C not blowing out forward facing vents

asked by on

The heat and A/C will only blow out the floor and windshield vents but not the forward facing vents. What do I need to replace to fix this issue?

My car has 51000 miles.
My car has an automatic transmission.

A: It’s not possible for me to tell you what e...

It’s not possible for me to tell you what exactly has failed on your car. I can however set you down the right path.

There are three components at work here. The mode switch that you turn on the dash, the mode door actuator that is mounted under the dash and the mode door itself. The most common failure for this system is the mode door actuator followed by the mode switch.

You will need to do some Googling to locate the actuator, but I would get to the actuator and tap on it. Often times this will free up a frozen actuator. If once you tap on it, it begins to move, I would begin by replacing the actuator. If the actuator is very difficult to replace, I would make sure this test is repeatable to be sure you haven’t missed something else. Check the connector, it could have a bad connection.

To do some testing at the mode switch, you will need a wiring diagram and remove the mode switch. With a test light, make sure you have power and ground at the appropriate terminals at the correct time. You can also do some trouble shooting that can help you diagnose the mode actuator. Often times accessing the mode switch first can be easier do to the hard to access nature of the actuator.

Lastly, if both those seem to be working, I have seen the mode door itself have problems. If you remove the mode actuator, you should be able to manually move the mode door to test its operation. If it binds or the the air isn’t directed out the correct vents when you move it around, you will need to remove the heater box and disassemble it to see what has failed at the door.

If you feel like you need assistance with these checks, enlist a qualified mechanic who can accurately diagnose this issue with your A/C and fix it accordingly.

Good luck!

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: engine overcooling; engine fan always on!

Hi Alex....yes, that sensor could be a possibility but there are other components in the circuit as well such as relays (that can stick on) and, although not as likely, there are possible wiring faults that can cause continuous power...

Q: Band need replaced, shop wants to rebuild transmission, is that necessary?

The transmission bands have a material on them that is similar to brake pad material. When the clutch bands wear the worn off material gets into the fluid and throughout the entire transmission. Also just because the band is the...

Q: Skipping, light rough idle, & smoking

Hi and thanks for contacting YourMechanic. Depending on what color the smoke is will determine what is happening with the engine. If there is heavy black smoke, then there is too much fuel in the cylinders and the fuel is...

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.