2002 CLK 55 A/C vent issue
Does anyone know or have the same problem? Also if there's a thread that referes to this please send me the link.
Thanks,
Joe V
South Florda
Mine hadn't been replaced for over 10 years and it made all the difference.
There are quite a lot of YouTube Videos about this.
Good Luck
David




Joe.........the HVAC is very complex and I seriously doubt you'll get a definitive thread/link solution.
Mercnotworking has already provided an exemplary suggestion that could explain why your vents are not providing the required air conditioning.
However, if you find that is not the issue, the good news is that, our W208/A208 HVAC push button control module (N22) has sufficient built in diagnostic/test capabilities, upon which even a shade-tree do-it-yourself could diagnose, troubleshoot and repair the system.
Specifically , there are 3 test ( e.g. for actual system values, present diagnostic trouble codes, as well as a flap test).
Our W208/A208's are not Spring chickens and most faults and the procedures/ interpretations of these test are all well known (READ: search is your friend).
Last edited by Serndipity; Jul 12, 2019 at 07:41 AM.
I did replace the A/C cabin filter and it was pretty bad. Unfortunately it did not solve the no vent issue. I even tried the A/C without the filter to see if it improved the air flow. No luck either.
I will however try the fault tests. I was able to find a thread that had all the instructions on how to get the codes.
I'm assuming there are flaps somewhere that are not opening causing the loud noise but no vent comes out.
Thank you all for the input
Joe
As others have said, the A/C system has been touched on a lot. I'm in Texas with my CLK55 and mine is black/black. Basically, it is hot as hell when I get it out and mine is working and I just charged it before the summer! I feel your pain.




I've included the above AC system values test even though you indicated that it works, except for lack of dashboard vent air flow. However, it's a very valuable tool to diagnose and repair various system components. As example, if in step 7, if your refrigerant pressure is low, you won't have icy cold and/or the compressor won't operate, but for about $25 you can purchase a can of R134A with pressure gauge to add refrigerant, which is an easy 5-10 minute DIY.
In the above, you will be able to see any system DTCs. Note that if a DTC is stored, in order for the system to operate properly, the DTC must be cleared (i.e. erased).
Some notes on the above flap test. Long vs short stroke refer to the being open or closed. This test helps to identity and repair a specific malfunctioning vent actuator, in which case there is some additional information needed (e.g. test/remedy section 32 that is not included), because you indicated that the air flow in all of your vents is weak or not existent.
If were me, the first thing I would suspect is a lack of system vacuum, which is required for vent actuator operation. As shown in the below diagram, the system vacuum (i.e. pressures) is supplied by the vehicle's air pump (located in the trunk passenger side), engine vacuum as well as stored in a reservoir (located in the front drivers side wheel well) and then distributed by a switchover value. I would begin by checking the vacuum system for leaks.
Added diagram for the cabin's vacuum line separation point.
Last edited by Serndipity; Jul 12, 2019 at 09:46 PM. Reason: Added the cabin's vacuum separation point diagram
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Joe
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Specifically, you may have inadvertently mucked up a line that supplies vacuum, though the firewall, to the Y11 Flap switchover valve, which is located inside the dash, behind the glove box.
Here are some links for more information.
https://www.benzworld.org/forums/c20...cuum-hose.html
https://www.benzworld.org/forums/w21...line-help.html
https://www.benzworld.org/forums/w21...cuum-hose.html
https://mbworld.org/forums/clk-class-w208/714194-where-vacuum-distribution-box.html
The bad news is that plastic components frequently disintegrate and break with age, the good news is that , if required, new replacement parts are readily available for very little dollars.
BTW, on our cabriolets (208.465), as noted in step 1 in the values test, whenever the roof is lowered, the N22 soft top controller overrides the B 10/4 in car temperature sensor. Ive found it advantageous to operate my air conditioner manually, instead of automatically. This way with the windows up, the wind screen in place and the A/C manually controlled as needed (e.g. on/off, temperature and fan speed), you can still enjoy driving a convertible, even on the hottest of Summer days.
Last edited by Serndipity; Jul 13, 2019 at 01:06 AM.




