Skip the auto shop - Our mechanics make house calls

Q: AC works but only blows warmest or coolest

asked by on

AC works but only blows coldest or warmest. If you start the car with the coolest on it blows cold (coldest it can be) and if you turn the button it stays the same until you reach the middle (or red line) - then it swap and blows out the warmest. And then it it doesn't change back to cold (it has done intermittently if I turn air off, turn to coldest, turn air on)

So the issue is that I cannot change temp when driving and it's earthed coldest or hottest.

It wasn't always like this, it just happened on day and has been like that for the last 6 months

Thanks for all help

My car has 130000 miles.
My car has an automatic transmission.

A: Hello, thanks for writing in. This is almos...

Hello, thanks for writing in. This is almost always caused by a bad blend door motor on this vehicle. I have rarely seen anything else fail on this vehicle that causes the same issue. It can be the module, but that is not common at all. The blend door motor fails under the dash and causes this. I usually test if first and make sure that the blend door is moving correctly and if it is then I replace the motor. If you want to have this AC problem checked, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this.

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

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: Heater broken

Hi there. This is a common problem with the specific vehicle you have. The AC and heater are separate from each other. However, your vehicle is infamous for having a leak in the heater core causing the air not to...

Q: Turn signals go fast/slow, headlights turn on/off, console beeps

The sockets for the turn signals on the C240 have been known to be problematic. Due to poor connection between the bulb and socket high resistance can result causing the turn signals not operate properly leading to a total bulb...

Q: How Does the Front Defroster Work in a Car?

Selecting the front defroster mode directs warm air up through the ducts at the base of the windshield in order to clear moisture in warm weather or frost in colder temperatures. In cold weather, the defroster becomes more effective after...

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 P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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.