Skip the auto shop - Our mechanics make house calls

Q: AC blows hot air - 2005 Mercedes-Benz SLK350

asked by on

I've been having some issues with the AC system in my car. The AC would start blowing hot air. This happened several times already. It would start working correctly when I restart the car after a while. Yesterday this occurred again so I restarted the car but the AC wasn't working properly. What is causing this?

Several heater/AC components could cause this problem. A bad interior temperature sensor, a bad heater/AC control module, or a bad heater control valve (electrically controlled) may be allowing the hot water valve to stay open, circulating hot water when it’s not appropriate. A YourMechanic professional can help diagnose your vehicles malfunctioning air conditioning and make 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: Hydraulic Fan

If the fan goes to 100 percent but does not reduce speed then the fan control module assembly needs to be replaced as an assembly as no parts are serviceable. A bad power steering pump may pass debris into the...

Q: Chemical odor in the car - 2007 Mercedes-Benz SLK350

Hot engine coolant, possibly leaking in the passenger compartment via the heater core, or a heater control valve, may be the source of this unpleasant smell. It doesn't take much of a leak (a few drops will do) to create...

Q: Car accelerates as if being feather then the engine shuts off

Hi there. There are a lot of possible issues that can cause this. If this occurred right after the replacement of the alternator then I would check the fuses first. It is possible that a wire got shorted during the...

Related articles

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...
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...
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...