Q: Heat and air controls broken

asked by on

The heater and air conditioning controls do not work right. All come on as defrost.

Hi. This can be caused by two things. There are actuators or motors under the dash that operate doors in the vent system. These door direct air to the different vent locations. The actuators can be ran by vacuums or they can be electronic. If they are vacuum operated, the vacuum line might have come off causing a leak. The default setting in this case is the defrost, so that is where it blows from. If the actuator is electronic and fails, the same will happen. Depending on the diagnosis, dash removal might be necessary to access the actuators. A qualified mechanic, such as one from YourMechanic, can inspect the AC for proper operation and replace any failing components.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Heat and air controls broken

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: I poured antifreeze in my car and it's still blowing out cold air when I turn the heater on

Hello. There are a couple of things to check here. When the antifreeze was added, was the cooling system thoroughly bled (with the heater turned to "Max" heat and fan? There could be air bubbles in the engine or heater...

Q: No oil on the dipstick

This engine requires 6 quarts of oil according to the service manual. I would check to see if the engine has an aftermarket engine oil cooler installed. You would see two hoses with an adapter above the oil filter and...

Q: How do you remove the torque converter bolts off the flywheel? 2005 GMC Envoy Denali

Hello - with the vehicle safely supported to provide clearance underneath - in between the engine oil and transmission pan, there is a large, funnel-shaped aluminum casting (called the bellhousing), that physically mounts the engine to the transmission. At the...

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...
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...
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.