Skip the auto shop - Our mechanics make house calls

Q: My a/c intermittently blows warm and cold air.

asked by on

My a/c works fine some of the time and then it starts blowing warm air and then back to cold. The compressor has been tested and is fine and I have had it charged. I live in Phoenix and use my air year round and really need to figure this out. Help!!

My car has 174000 miles.
My car has an automatic transmission.

It is possible that your blend door actuator could be failing and going back to the default position. Many vehicles will default the blend door to heat mode. When the blend door actuator fails, it will automatically revert the door back to this default setting.

I would recommend having your blend door actuator tested using the manufacturer’s recommended procedure by a qualified technician such as one from YourMechanic. One of our mobile technicians will be able to come to your home or office diagnose the issue with your AC and help you 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: Car shaking during acceleration and shifting between gears

This condition sounds like one BMW has noted on a technical service bulletin (TSB) concerning a software issue in the engine control module. There has been an updated software version developed by BMW but you will need to have this...

Q: How do I adjust the automatic temperature control (ATC)?

The automatic temperature control (ATC) system allows both the driver and the front seat passenger to have different temperature settings. The ATC panel has both a “MODE” and a “BLOWER” control knob; set both of these to “Auto.” Then, use...

Q: Oil leak - how to clean? 2000 Honda

Hi there - your best bet is to get an engine degreaser from your local auto parts store to clean your engine. There are many bio-friendly choices these days. Don't use kerosene or other petroleum variants to do this. Warm...

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...