Climate Control Vacuum Question
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Newbie
Joined: May 2002
Posts: 3
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From: Las Vegas, NV
1994 Mercedes C280
Climate Control Vacuum Question
When my air is on and I press the accelerator, the air stops blowing out of the center vents and starts blowing out of the defroster. Anyone have any experience with this? My first guess is the control valve behing the glove box, but anyone who's had this happen may know exactly what it is.
Thanks, Adam.
Thanks, Adam.
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Joined: Mar 2002
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From: Newport Beach, CA
1995 C280 & 2002 CLK320 Cabrio
I have the same problem... though now, my vacuum system is totally inoperative. Air only comes out of the defrost. Recirc does not work... and it doesn't close the when the system is turned off... so I get a ton of wind in the car when driving on the freeway!
It is definitly a vacuum leak somewhere in the CC system!
It is definitly a vacuum leak somewhere in the CC system!
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Joined: Aug 2002
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From: South Florida
1997 C280
PLEASE HELP!
It's starting to get hot down here in FL and I have the same problem. 1997 c280, 60K Miles. No matter what setting i put on the climate control, the air blows from only the corner vents and the defroster. No air blows from the center vents. The climate control backlight is also not lit when i turn on the headlights. The blower seems to be working fine, it just looks like the "flaps" arent functioning. Are these vacuum controlled??The temperature setting is also functioning properly. (If i make the temperature warmer it then blows hot air out of the corner vents and the defroster).
Some posts suggest vacuum line leaks etc. Where are these lines located in the car??? (behind the dash???)
I would also like to know where is the bulb that needs to be replaced for the backlight of the climate control.
I would like to try and solve this myself so any help with this issue would be greatly appreciated.
Thanks,
Tony
Some posts suggest vacuum line leaks etc. Where are these lines located in the car??? (behind the dash???)
I would also like to know where is the bulb that needs to be replaced for the backlight of the climate control.
I would like to try and solve this myself so any help with this issue would be greatly appreciated.
Thanks,
Tony
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Joined: Sep 2002
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Climate Control Vacuum Question
My '96 C280 has this same problem. The vacuum pump runs too much and the center A/C vent turns itself off and on, but my door locks are working fine. Has anyone found a likely cause of the leak? I'd appreciate any insight on this before I go to the MB dealer and bend over...
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Joined: Apr 2002
Posts: 333
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From: NYC
red bicycle
I just posted this in Tech Talk:
It's the PSE pump...mine is making a slight droning noise...but everything works fine. I've had it replaced before...a month after the car went off warranty, the rear defroster stopped working. The part was $1000, but the dealer did the work for free (considering it was just off warranty).
Check out this thread: https://mbworld.org/forums/showthrea...threadid=12996
From Patrick: "Yep, it is the PSE (Pneumatische SteuerEinheit), a sort of vacuum pump (however it also has electric/electronic functions). It is normal when you here it while locking or unlocking the car. When you here it more and/or longer than before you may have a leak. When you hear it while driving, it must be that air intake manifold pressure becomes too low. Under 300mBar (I do not know how much that is in American values, PSi's or whatever,...) the PSE "helps" to maintain all vacuum controlled things."
It's the PSE pump...mine is making a slight droning noise...but everything works fine. I've had it replaced before...a month after the car went off warranty, the rear defroster stopped working. The part was $1000, but the dealer did the work for free (considering it was just off warranty).
Check out this thread: https://mbworld.org/forums/showthrea...threadid=12996
From Patrick: "Yep, it is the PSE (Pneumatische SteuerEinheit), a sort of vacuum pump (however it also has electric/electronic functions). It is normal when you here it while locking or unlocking the car. When you here it more and/or longer than before you may have a leak. When you hear it while driving, it must be that air intake manifold pressure becomes too low. Under 300mBar (I do not know how much that is in American values, PSi's or whatever,...) the PSE "helps" to maintain all vacuum controlled things."
