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?

A: Several heater/AC components could cause th...

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・Save up to 30%

Get a quote

What others are asking

Q: Car lost power and stalled

Hello there. It's kind of odd that your 2011 Mazda2 is exhibiting this issue with so few miles on it. However, many different faults can cause the vehicle to stall. The most common would be the fuel pump, fuel filter,...

Q: Tensioner needs replacing

Hi. The belt tensioner pulley may need to be replaced if it is chirping. The chirping noise comes from the bearing inside the pulley that is worn out. It is typical for them to be replaced along with the serpentine...

Q: Car will crank but no start... Fuel pump not coming on. New pump, relay, etc. Will start when hot wire runs from pump wires to bat

There are a couple of approaches to take here - either start from the battery and work "towards" the fuel pump, fuse box, ignition switch, fuel pump relay, and wiring connections in between. Or, as you have done, start at...

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...