carbizindio

Thank you for all the pictures, it helps a lot. I started on this tsb the other day, what I was unsure about is how many motor lever arm's are under the dash. I show in your photos only 2.

All data tells me there are many flaps inside, I would like to change every arm while its apart. Can you confirm there is only 2 of these arms under the dash?

King Z

I have the clicking noise as well. I have a 2002 C320 and I am assuming that it will be the same way in my car. Am I correct?

carbizindio

yes, also check the gears for the 2 center vent motors while every thing is torn apart.

King Z

The noise seems to be coming from the right center. Does the whole thing have to be done? This is a very long process. Have yo done this job before?

carbizindio

with his photos the job doesn't take very long. does your right and left center vents work correctly when playing with the switch? if they do than you have to take every thing apart per his photos to get to the levers.

ok303

excellent guide, this job is next on my list. thank you

Kreuzfeuer

You win the award for most useful post of the month, haha! Excellent writeup.

testknight

This thread needs a LOT of credit. Great write up!

krazzdav

Great BIG thanks to Racin_fool, liveniceguy and Wilsophia for the write up and
pictures!!!

I put together a PDF with the write up and all of the pics compiled with each other since I am going to be doing this myself.....enjoy!!! Unfortunately had to split it up into 3 files to post here.

W203 Air Conditioner Stepper Motor Repair P1 of 3.pdf

W203 Air Conditioner Stepper Motor Repair P2 of 3.pdf

W203 Air Conditioner Stepper Motor Repair P3 of 3.pdf

fjmrf

You are the man!!! THANKS!!!!

Rubin85

thanks for pdf next week I need to do the same :/

djwall1000

Hi All

Thanks for all the excellent work done on this thread.

I have the dreaded clicking noise but cannot figure out which stepper motor or arm is involved. My noise is 1 click per second (ish possibly a little quicker) for 30secs.

When I try to diagnose by turning on / off vents they all seem to be working, indicating that none of the arms are broken?

Any suggestions would be greatly appreciated.

Dave

krazzdav

Dave it's going to be either one of the arms cracked or a stepper motor. The only way to tell for sure is to actually take the dash apart unfortunately. I am not sure if the STAR DAS would tell you anything further in identifying which motor because I didn't have it at the time I fixed mine.
I had both cracked arms and a bad stepper motor.

gwin

At least you didn't spend 4 hours removing half the dash and then realising it wasn't the footwell having issues, and is one of the motors behind the dash which requires entire removal of the dash assembly to get to the A/C tunnels. And also spending $50 on linkages you don't need.

djwall1

haha - I have spent the money on linkages! Am trying to figure out whether I should buy one of the motors before I take the dash apart...

Had read somewhere that you can diagnose by testing which vent is either stuck on or stuck off. All of mine work - just have the clicking sound.

Will post it to youtube and then put up a link and then come back for advice.

gwin

Yea, I'm starting to learn that, don't buy the part unless you are SURE it's broken, unless of course you're doing preventative or upgrades.

My car is almost a weekend car now, most of the time it's in downtime because I have to strip the car to get it out before actually ordering, then it takes 2 weeks to get here at least.

I basically lived with the clicking noise, all my A/C works fine. Can't be bothered anymore

djwall1

Thanks again for the advice.

If anyone can have a quick peek at the following and give an opinion that would be great

www.youtube.com/watch?v=jZknjIl6fBU

As mentioned the vents for the A/C all appear to be working - both on/off which suggests no stepper motor / linkage issue?

Thanks
Dave

afurkan

Thanks man. Very good job and great DIY.
I have same problem on my 2003 C320 but clicking sound coming from driver side (LHD) foot area.
I will do it at this weekend.

afurkan

I worked for this issue whole weekend and i figured out what the problem is. The problem in my car is different than yours. The damper linkages in the picture below were replaced with new ones, but the idiot whoever did this fixated the Right(R) linkage to both sides instead of fixating Left(L) linkage to the left side. if you look through closely you can see the angle differences between R and L linkages.

Access to stepper motors:




Angles differences:


This angle difference have caused cogwheels to break in the step motor in time. I purchased a new step motor and a pair of new damper linkage and solved the problem by setting it up to the right side.

Broken stepper motor gears




new stepper motor:


End of Day:

baha411

Here are two videos showing the stepper motor problem and how to fix it:

jakel01

Just completed this job over the weekend. It was not fun, but pretty straight forward. The worst part was getting the large black plastic cage out. The only way to get it out without removing the top of the dash is to break it out. But on my 2003, who cares... Pretty sure I mixed up which arm is which, but I don't see how it matters, isn't that what the calibration procedure is supposed to fix?

Slava30490

Yes, if you assemble everything correct calibration will go smoothly and all will be set up. During calibration each motor will find and remember final positions.

jakel01

Further follow up, the two arms I removed from the car both had the same hex orientation, which further leads me to believe it doesn't matter which goes where, just do the calibration after. I've driven the car 3-4 times a week since I did the repair two months ago, and no problems or clicking.