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.

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: Ac hot air. 2001 Dodge Stratus

Hi there. You should begin by finding the leak in order to determine what it would take to fix it. Adding refrigerant to the system may make it work now but you could overcharge it and cause more problems in...

Q: Do strut bearings wear out? If they are worn out or bad, will it cause further damage if I continue to use the car?

Yes strut bearings will wear out. The first signs of worn strut bearings is the steering may jerk when turning at low speeds or parking maneuvers. As the bearing gets worse you will start to notice the steering becoming noisy...

Q: Water getting into car

Hello. During it's operation, the air conditioning system will come across a large amount of condensation. This condensation gathers around the evaporator and runs off through a drain. You may see water dripping from the car on a hot summer...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...