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Discussion Starter #1
I tried to search and found some info, but I am not clear as to why I can blow warm air in any desired direction on the passenger side, while the driver side outlets are all blowing cold air.
that happens no matter whether I am in manual or auto mode.
At the moment I cannot drive the car as it does not clear the front windshield of moisture/ice.... very frustrating.
I understand that there may be motor/flaps for where the air goes, but which part/component is responsible for putting the hot coolant to the driver side only? is that a valve in the coolant circuit or is all that done in "air ducts/circuits"?
i.e. is there just one hot and one cold spot and the air gets mixed going through ? if so, where would that be.
PS: I already did the "calibartion procedure with RECIRC and FRONT DEFROG which it passed, but did not change anything.

Appreciate any help you can provide. Thanks.
 

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There is no duo-valve won the W203 so it's all done via the dampers in the ducts. I am surprised that if there is a damper issue that the test would have passed. Are you sure it did? If so, the test should have stopped on its own about 20-30 seconds.
 

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Werner.. Welcome to the club.. Both of my MBs (w203, m163) have flap failures.. On the w203, it's the foot flap.. I can live with that.. On the ML, it's the heater core, ac condenser flap.. Something that I can not live with.. Unfortunately, the repair on either requires the dash has to come out.. BIG BUCKS, if you have someone else do it.. A big pain in the ass, if you do it.. How ask yourself, "Am I willing drop a $1,000 plus on a 13 year old car to defrost the windshield" or look for a work around that can get me by.. They make little cig lighter heaters that can defrost your windshield for under $20.. On my ML I was able to get in behind the glove box and make it into a mechanical "summer, winter mode flap" so I didn't have to rip my dash apart.. Which and where your flap failure is, I don't know.. But one thing for sure, to replace motors and flap assemblies... The damn dash has to come out..
 

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An alternative to removing the dash would be to cut into the duct for access. You'd have to know exactly where to cut, and you still may have to removes parts of the dash (center stack, glove compartment). Also, removing the fan can help with access, too. I have WIS docs for all of them here:


Scroll to the bottom - they all start with the word "Ventilation". Note that this is for the W209 with the high-line full dual control ACC. For the base ACC controls without full dual controls, it's the same but missing about 3 or 4 of the dampers and servos.
 

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Discussion Starter #5
There is no duo-valve won the W203 so it's all done via the dampers in the ducts. I am surprised that if there is a damper issue that the test would have passed. Are you sure it did? If so, the test should have stopped on its own about 20-30 seconds.
So I did that test again.. twice.
With engine running..pushing defrost and recirculation for a couple seconds..they start blinking.. one yellow one red. Back and forth.. then after about 15+ seconds both stop. I can hear stuff moving around in the dash.
If that would be an ok test.... could it be a broken linkage to a flap?
 

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Discussion Starter #6
Werner.. Welcome to the club.. Both of my MBs (w203, m163) have flap failures.. On the w203, it's the foot flap.. I can live with that.. On the ML, it's the heater core, ac condenser flap.. Something that I can not live with.. Unfortunately, the repair on either requires the dash has to come out.. BIG BUCKS, if you have someone else do it.. A big pain in the ass, if you do it.. How ask yourself, "Am I willing drop a $1,000 plus on a 13 year old car to defrost the windshield" or look for a work around that can get me by.. They make little cig lighter heaters that can defrost your windshield for under $20.. On my ML I was able to get in behind the glove box and make it into a mechanical "summer, winter mode flap" so I didn't have to rip my dash apart.. Which and where your flap failure is, I don't know.. But one thing for sure, to replace motors and flap assemblies... The damn dash has to come out..
I hear you. I got no garage.... have tried those little 12vdc plug in heater fans.... joke.
Now got a 115vac small heater with a timer so I can warm up the car....
But that only works at the house. Not at work to go home.
Yep.. not ready to spend major money on fixing it. But one sure has to at least try .
 

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Discussion Starter #7
An alternative to removing the dash would be to cut into the duct for access. You'd have to know exactly where to cut, and you still may have to removes parts of the dash (center stack, glove compartment). Also, removing the fan can help with access, too. I have WIS docs for all of them here:


Scroll to the bottom - they all start with the word "Ventilation". Note that this is for the W209 with the high-line full dual control ACC. For the base ACC controls without full dual controls, it's the same but missing about 3 or 4 of the dampers and servos.
I appreciate your help rodney.
I looked at those files before but dont understand which flap would be responsible to direct either hot or cold air to the driver side.
The passenger side works fine.
 

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Werner,.. Here's something you can check, The "fresh air" intake.. The recirculated /outside duct is on the firewall under the hood..behind the battery... Make sure that's closing, that way at least you're not sucking in freezing ass air on the driver's side..
 

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Discussion Starter #9
Werner,.. Here's something you can check, The "fresh air" intake.. The recirculated /outside duct is on the firewall under the hood..behind the battery... Make sure that's closing, that way at least you're not sucking in freezing ass air on the driver's side..
thanks for the tip. will try check this out... do you mean to watch out for this during the testing of the ACC control, or just in general in my normal setup with AUTO and AC turned ON?
 

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MY05 CLK55 AMG ,CLK320,Former,C180 Kompressor,Jensen Healey,Ford Capri V6,Alfa GTV.
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I think it may be the Left blended air flap positioning motor, M2/6 ,,which is roughly located right under the dash in the middle. Unfortunately quite hard to get at ..
as stated above ,,you have to remove the centre console and more to get at it ,,,not easy ..
 

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Ya, how ever you want to do it.. Pull inspection plate off (you can see the flap).. Put the heat on, hit recir.. button on the control, make sure the flap closes.. If I can recall correctly, there's a filter in there.. Pull filter out to see the flap
 

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I appreciate your help rodney.
I looked at those files before but dont understand which flap would be responsible to direct either hot or cold air to the driver side.
The passenger side works fine.
I believe it's the left blend flap:


It is possible that the servo is working correctly, but the linkage or damper is failing. Normally, that prevents the servo from positioning correctly and the test fails, but it is possible that the malfunction is "just right" that the servo has full movement but the flap does not open and close properly.

This is one you can access fairly easily from under the dash. it might be worth a look.
 

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My son and I are going to tackle this in Spring on his C230 once it warms up. He also has the sticky/broken footwell flap "click of death".

From what I have read, the dash removal really isn't that difficult. It's just a very large "time suck" as there are lots of things to remove on your way to getting there, and that is why it costs so much at a shop. It can take the better part of an entire day by the time you put it all back together (or so I have read!)
 

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Dash removal is not too bad. When you have to remove the duct, which requires removing the heater core and the evaporator, that's when it become a real chore.
 

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Discussion Starter #15
My son and I are going to tackle this in Spring on his C230 once it warms up. He also has the sticky/broken footwell flap "click of death".

From what I have read, the dash removal really isn't that difficult. It's just a very large "time suck" as there are lots of things to remove on your way to getting there, and that is why it costs so much at a shop. It can take the better part of an entire day by the time you put it all back together (or so I have read!)
well... I wish you good luck. So far i have restrained myself from doing anything "inside the dash"..... the more stuff has to come off... the more can break.....
It might be very helpful for all of us if you can "document/take pics" of your journey.
 

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Discussion Starter #16
I believe it's the left blend flap:


It is possible that the servo is working correctly, but the linkage or damper is failing. Normally, that prevents the servo from positioning correctly and the test fails, but it is possible that the malfunction is "just right" that the servo has full movement but the flap does not open and close properly.

This is one you can access fairly easily from under the dash. it might be worth a look.
well... that M2/6 looks almost "too easy" but then again another member mentioned it is hard to get at. The graphics is a bit confusing, but the text simply states to remove the 3 screws. disconnect electric.... but then you "need that diagnosis tool"? If I pass the ACC test... I don't believe I need that tool, do i?
 

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Technically, you are supposed to normalize the servo position with SDS, but the DEFOG+RECIRC "test" should also do it. I have replaced a few AAC servos and non actually needed any normalization - they just worked.
 

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Discussion Starter #18
Technically, you are supposed to normalize the servo position with SDS, but the DEFOG+RECIRC "test" should also do it. I have replaced a few AAC servos and non actually needed any normalization - they just worked.
THanks! that is what I was hoping for an answer. I still have a feeling that it is the linkage... but then again... we will find out after diving into that dash. Found a video on youtube where a guy is just doing that job of replacing the M2/6.... looks like a bit of pain to get to at the end.. but sure looks doable.
will report back when/after I decided to have no more excuses and just do it.
 
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