Skip the auto shop - Our mechanics make house calls

Q: Mode control on air conditioning does not work.

asked by on

EverytI me i turn on my car and turn on the air, it only comes out of the defrost vents. Even if I changet it to other modesites it stays there.

My car has 70860 miles.
My car has an automatic transmission.

A: Your car comes equipped with a possible man...

Your car comes equipped with a possible manual and an automatic heating and A/C system. The automatic system is a set it and forget it system. You set the desired temperature and the car will adjust itself accordingly. The manual system requires you to adjust the temperature as needed. The two systems use all the same components with the exception of the temperature control module. Specifically the automatic system uses a module to control the climate in your passenger compartment.

Both systems have what is known as a mode door actuator. This is an electric motor that moves the mode door under your dash. The mode door actuator is the most common failure in most HVAC systems. The HVAC module in the automatic system tells the mode door what position to be in. If it has failed, it will not send a signal to the mode door actuator. The manual system has a mode position switch that will also send a signal to the mode door actuator. If it has failed, the result will be the same.

The previously listed components are all there is to the mode control in a typical HVAC system. Aside from them, you will need to check all the fuses. Be sure to do this first. If you need help with any of this, a certified mechanic, such as one from YourMechanic can come to your car’s location to diagnose your air vents system and make the necessary repairs.

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: Loud noise and tire locking up while driving. The left ball joint control arm is bad.

Hi there. Knowing the lower ball joint is bad leads me to believe that the really loud noise and wheel lock-up may be related. A bad lower ball joint typically will cause the vehicle to track (veer) towards any groove...

Q: Engine has a misfire

There are a number of things that can cause poor fuel mileage, which may also cause it to misfire. A faulty camshaft position sensor is one of them. The camshaft position sensor is a magnetic sensor that monitors camshaft speed...

Q: My 2004 Acura TL is not blowing cold air. I have gotten a new A/C compressor as well just last year. It started acting up in January of 2017.

Hi there. The air conditioning system can have many things that could contribute to a heat cycle condition. Check the following conditions to find the source of heating issue: Check The condenser for any dirt or plugged up vent...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
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.