hrothgar02

My AC will stop working suddenly and 10 mintues later decide to work perfectly fine....then stop then work regularly. I will go 2 weeks without any issues and then suddenly it stops working. The MB shop caught this when I had the car under warranty and they apparently replaced a blower regulator but that clearly did not resolve the issue. When the AC stopped working, I attempted to press the auto climate button and all the car did was make a really loud blowing noise with nothing coming out of the vents; then 2 minutes later the AC would work full blast...then stop.

Has anyone else have this issue? I have a 2004 cabriolet with 33K miles on it.

Thank you in advance for your help,
Sweaty cheeks in Houston.

ac_schnauzer

when it's not working would you get any air coming through the vents? if not, it probably has something to do with the blower.

hrothgar02

The compressor is running but nothing is coming out of the vents. Sometimes the AC goes crazy by rerouting the air below, then above and then finally through the vents.

ac_schnauzer

probably the blower. are you going to replace it yourself or get the dealership to do it? Let us know how it goes.

tbenz

sounds like you may a bad a/c control panel,but could be almost anything. if you live in Houston call Doug at Alex Rodriguez Mercedes and they will pick your car up and leave you a loaner car for free,what a great service.just have to pick up the phone and make an appointment.

OLDSCHOOLRICE

Sounds like you might have a bad stepper motor if you say that you hear the blower motor running but the air is being blown out of here or there or not coming out at all. There are several stepper motors on your car that control everything from where the air blows, to recirculated air or fresh air, and blending of the hot and or cold air with the fresh air to achieve the right temp. If one of the motors that controls which vents the air blows from goes bad it would likely cause a problem like the one you're describing.

Might be a faulty a/c control module as well.

When you take it to the dealer again there are tests that they can do to make shure that all the stepper motors are working properly. Just make sure that you are very descriptive of the issue that you are having, because when I read your first post what you described sounded like the blower motor wasn't working at all. Then your later post actually explains that the blower is operating but the air isn't coming out.

Good luck.

gregc

I am in Austin. My car did the exact same thing. I took to dealer and they said nothing was wrong then put leak finder in it. My extended warr would not cover since it was not 'broken'. That cost me $400.

The did charge the system will a couple of pounds and all was good, for a while. Started to do the exact same as yours. It was all over the place.

Went back and raised crap.

Come to find out, pressure leak only at times as compressor is running. They replaced compressor and high pressure hose to unit. All is fine now.

Dealer mech said that inside the compressor is a one way value. This thing will go nuts sometimes causes all sorts of things.

newguy2008

My "EC" button was pressed, and now it won't turn off, even after pressing and holding it down. The light stays on even if the heater/a/c control unit is off. Anyone know how to reset or turn this off? Will disconnecting the battery shut this off?

My problem all started when the AC wasn't blowing cold air. I tried switching between "EC" and the regular setting to get it to get cold, but cold air was still not coming out of the vents.

Anyone experience this? I have a 2002 CLK 430.

hrothgar02

To all,

Thank you for the suggestions. I will bring up all of the possibilities when I take it into the dealer.