Weird A/C anomaly
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MBWorld Fanatic!
Joined: Jul 2008
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2019 G70 6MT & 2022 Ford Maverick XL
Weird A/C anomaly
Today it was 92 degrees out here in GA and very humid. The Benz stays outside now and had been baking since Sunday morning. When I got in the car and started it, the A/C light on the climate control panel was illuminated. The fan speed was set to 0-OFF and the AUTO function was not on, either. Only the A/C light was on, no fan was running or air movement at all. I turned the fan on, then back off, and the light went out as normal. Then I turned the fan to max speed and the A/C seemed to take just a bit longer to get cold but then worked just as well as it always has.
This ever happened to anyone here? Can't find anything in the manual that says this should happen for any reason.
Background: On really hot summer days, I have to control the fan speed manually because the system shuts down on its own with the "AUTO" function engaged. It's done this for 2 years now without any other effects. I've read about this problem on here a few times but haven't replaced the control panel because it is still working fine manually.
This ever happened to anyone here? Can't find anything in the manual that says this should happen for any reason.
Background: On really hot summer days, I have to control the fan speed manually because the system shuts down on its own with the "AUTO" function engaged. It's done this for 2 years now without any other effects. I've read about this problem on here a few times but haven't replaced the control panel because it is still working fine manually.
Super Member
Joined: May 2009
Posts: 818
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From: Atlanta, GA
'02 C230 Coupe (Me) '03 SLK320 6MT (Wife)
Odd. I can't help with this, other than to say that I know problems in the control panel can be very, very weird: Our SLK had an issue where if you touched the brakes, or turn signal, the A/C would shut off -- and wouldn't come back on. But if you turned it OFF, then honked the horn, you could turn it back on. (WTF?!? - and don't ask me how a friend figured out that combination!) Took it in under warranty, and they found a short in the A/C controls, replaced the control panel and it has worked like a charm ever since.
My uneducated guess is just another symptom.
My uneducated guess is just another symptom.
MBWorld Fanatic!
Joined: Feb 2009
Posts: 5,054
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From: fort worth, tx
06 C230 SS 6spd
I've had my AC light come on when I forget to turn the ac off before I turn the car off and when i get back in the ac light is on. I just turn the fan on and back off and the light goes away. I wouldnt be too concerned, I've done it a couple of times and my ac works perfectly fine. I've even had it where I didnt turn the ac off before I turned the car off with the fan still on and when I get back in the ac light is on and the fan should be running since its in the on position but no air is blowing. I just do the same thing and turn it on and off and it works normally.
Member
Joined: Feb 2010
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2006 c230
mine does it all the time i found out if the fan speed is turned to 0 and i start the car the fan will blow like its on 1 if u turn the fan to past 0 it shuts off, when i let it go it comes back on. so what i do is turn it on to 3 then off and it stays off, i have a feeling my ac control panel or more specifically my fan speed knob has a bad or dirty contact.
Mine has a leak and constant hissing sound when on. Hi5 guys! 
