Clicking Stepper motor A32m2

PierreK123

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W203 C320
Hi all,
I think we all know about the dreaded clicking in the dash especially on the C320 which it's around 11 motors/sensors.
In referring to the A32m2 (see attached diagram) I've read up that this is an expensive (read labor intensive) problem to fix and chances are that it might come back in a year.
A out-the box thinking is if it is at all possible to by-pass or disable the said stepper motor either by simply removing it or the power to it or even from the fuse box (if it can be isolated)
What would the result be?
Apparently this will NOT cause a permanent fault message on the dash which is great news.

I'm aware that this will influence the climate control but I'm wondering to what extend will the impact be worse with a flap/stepper motor malfunctioning, compare to being disabled since there are other air vents so it's not like you will overheat or freeze to death :)

Anyone ever disabled it before or know where the relay is that controls it instead of stripping the dash?
Would be great if I can test the effect via the fusebox removing a fuse or relay...
 

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Paul Goff

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2002 C220CDi CD Estate
Morning Pierre,

I have a more basic model than yours and it has been clicking since I got it!
UNTIL recently, when I started doing the auto setup procedure with maximum prejudice:cool:.

Just doing it for a couple of minutes with everything "as was" didn't have any effect, but found that; with all the outlets closed, the fan on max and while actually driving for several miles:eek:, things are improved:)
No clicking now, and the vents to feet seem to be working again, still not opening the screen vents though:(

Try the set up procedure before doing anything else, get back to me if you need to know how;)

PS, I do all this fiddling about on a long bypassed stretch of rural and long bypassed Trunk Road, which is now almost empty!
 
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PierreK123

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@Paul, thanks for the reply - do you have links to the "set up procedure"
 

umblecumbuz

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S204 and CLC 204 cdi, MX5, Kia Soul
As I remember, the fault can be caused by a stuck flap or stripped teeth on a flap. Either way, isolating the motor (believe there are six in total within the heating/aircon system) will not 'fix' anything except the clicking sound itself, and may isolate more than you intended. The downside would be restricted control of the air outlets - but you've got a bit of that anyway.

A friend with a 203 squirted wd40 through his heating inlet with the fan on slow while juggling with the controls, after removing the pollen filter, and that seemed to fix his issue - for the time being. Bet the interior smelled! He had been told that cutting a hand-sized hole in the rhs of the glove box would enable access for a fix, but chickened out.
 
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PierreK123

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@umblecumbuz - some nice ideas you have. I would not doubt go for the cutting of the hole but only if I knew exactly where to cut it and secondly - I find it strange that you only need a hand-sized hole to do the job. Surely removing only the glove-box is not such a big job and would give you more room to work. But from other posts I read it seems like you have to take out most of the dash not just the glove-box.
On a positive side, mine has not made a sounds since I did the reset procedure... :)
 

Paul Goff

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@Paul, thanks for the reply - do you have links to the "set up procedure"
Ignition on
Press and hold Demist (NOT heated windows) & Recirc buttons together for several seconds
Set up will start, system will cycle through all directions and full Hot to full cold continously
IF it thinks all is OK the set up will stop itself after a couple of cycles
If not OK it will just keep going until you switch off the ignition.

I have been doing this with the fan on full and with every combination of vents shut to open + everything in between I can think of!

It certainly hasn't cured mine, it just keeps cycling until I get home and switch off, but the clicking has stopped and I appear to get a little more function every time I try it;)

Not ideal, however paying some £500 in labour + parts is not possible, and certainly not very wise on my 15 year old car.

Perhaps this should be (is?) part of the servicing schedule! I have an extensive HVAC background and stroking every motorized valve and damper through their full movement is part of routine maintenance. Left to it's own devices for years the system will slowly drift away from the optimum performance and of course things can seize completely.
 
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PierreK123

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@Paul - thanks for the routine

From above:
On a positive side, mine has not made a sounds since I did the reset procedure... :)
 

Paul Goff

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2002 C220CDi CD Estate
As I remember, the fault can be caused by a stuck flap or stripped teeth on a flap. Either way, isolating the motor (believe there are six in total within the heating/aircon system) will not 'fix' anything except the clicking sound itself, and may isolate more than you intended. The downside would be restricted control of the air outlets - but you've got a bit of that anyway.

A friend with a 203 squirted wd40 through his heating inlet with the fan on slow while juggling with the controls, after removing the pollen filter, and that seemed to fix his issue - for the time being. Bet the interior smelled! He had been told that cutting a hand-sized hole in the rhs of the glove box would enable access for a fix, but chickened out.
Liking the WD40 idea:geek:
 


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