W209 Infamous stepper motor click inside dash

[Coruscator]

Hi,

It happend in my car about 6 months ago. I did attempt to take the dash apart to get to it at the time but only got so far.

I couldn't see/understand how to remove the top half of the dash, the part where the air vents are fitted.

I was easily able to remove;

glove box
centre console
radio
a/c controls
top bank of buttons (hazzard switch)
clocks behind steering wheel
facia below steering wheel
all air vents
grill in the top of the top half of dash
side pillar covers (edge of windscreen)

but thats where I ran into a problem. I couldn't for the life of me see any screws of fixings to enable me to
remove the top half of the dash. They fix them securely thats for sure.

So I gave up because I wasn't prepaired to force or break anything to get to the stepper motor and I
discovered if I turned my carbon filter on it did not click. So thats the way it stayed until now.

Can anyone advise as to how the top half of the dash is removed? Preferably with some photos,
if thats not too much to ask.

The photo shows my progress the last time I attempted it. I managed to get further than the picture
shows but it gives you an idea of the dash im talking about.

Thanks

 

[Coruscator]

I've scoured the internet for information about removing the top half of the
dashboard and can find very little about it.

So I'm wondering now that if, in fact the top half may not need to be removed after all.

The only decent info I can find on it is for a pre facelift model, which mine isnt.

I couldn't see a stepper motor after I removed all the parts listed in my
previous post. But there was a black plastic 'cage' into which the radio and
climate controlls, etc fit into and I couldn't see how to remove that either.

If I don't have to remove the top half of the dash, then can anyone show me
how this black plastic 'cage' is supposed to be removed. Maybe then I will be
able to get to the offending stepper motor.

thanks.

 

[AMGeed]

This article looks like it could help.Its for an E Class 2003/09 but the dash is practically the same.

Mercedes-Benz W211 Upper Dashboard Cover Replacement (2003-2009) E320, E500, E55 | Pelican Parts DIY Maintenance Article

 

[rf065]

Have you tried doing a reset first?
Can't remember the exact way to do it but it worked on mine.

Russ

 

[Coruscator]

Have you tried doing a reset first?
Can't remember the exact way to do it but it worked on mine.

Russ

Hi ive just tried the reset and the clicking continues throughout the whole testing procedure.

The testing procedure didn't stop either it just kept cycling, I had to turn the key off to stop it.


Its worth mentioning that the clicking stops when I switch my carbon filter on.

Does this give any clues as to which motor is clicking? The sound is coming from underneath the left
hand side of the metal grill insert in the top half of the dash.

Also, now I think about it the rear center console blowers aren't nearly as powerful as the
front ones either but I'm not sure if it was like this when I bought the car (2 years ago) or
if its happend since the clicking. (sorry)

 

[Coruscator]

This article looks like it could help.Its for an E Class 2003/09 but the dash is practically the same.

Mercedes-Benz W211 Upper Dashboard Cover Replacement (2003-2009) E320, E500, E55 | Pelican Parts DIY Maintenance Article

Oh wow, thank you. This is excellent.

I'm not so sure if I need to go this far to get to my stepper motors now,
but I might be wrong.

If I am, this will come in very handy.

Thanks buddy, good find. :0)

 

[rf065]

Also, now I think about it the rear center console blowers aren't nearly as powerful as the
front ones either but I'm not sure if it was like this when I bought the car (2 years ago) or
if its happend since the clicking. (sorry)

The rear blowers are only really powerful on one of the settings, all the others direct more air away from the rears making them a lot weaker.

Russ

 

[Coruscator]

The rear blowers are only really powerful on one of the settings, all the others direct more air away from the rears making them a lot weaker.

Russ

Ahh thats good to know because thats what I'm experiencing.
I can get good flow through them but only on one setting like you said (think its the face setting)
and then only with all the other vents closed. Not great for when the kiddies are in the back and its cold.

Or for me sitting in the front either, ha.

 

[Codger49]

Coruscator,

I have a pdf of the WIS document "GF83-40-P2183Q Actuator motors for comfort automatic air conditioning, location/task/function" which may be helpful in your troubleshooting.

Drop me your email address in a PM if you would like a copy.

 

[Lecky]

Done this job twice now. The fact that you don't get the noise when you select the active carbon filter button would suggest to me that your a32m2 stepper motor - or rather the linkage cogs have gone. See my recent post below.

http://www.mbclub.co.uk/forums/electronics/207785-a32m2-charcoal-filter-flap-motor.html

The upper dash is fairly simple. You need to remove the piller trims and a few screws underneath the dash. There are two more hidden under little covers right next to the windscreen - look at the dash from outside the car through the screen to see them. The cogs you need unfortunately only come in a kit which costs around £40 from MB. Worth changing some of the other cogs/lever arms while you are in there.

A good thread is here-

Noisy Air Conditioner ?? Stepper Motor Replacement / Clicking & Hissing - MBWorld.org Forums

Let me know if you need any more info.

 

[Coruscator]

Done this job twice now. The fact that you don't get the noise when you select the active carbon filter button would suggest to me that your a32m2 stepper motor - or rather the linkage cogs have gone. See my recent post below.

http://www.mbclub.co.uk/forums/electronics/207785-a32m2-charcoal-filter-flap-motor.html

The upper dash is fairly simple. You need to remove the piller trims and a few screws underneath the dash. There are two more hidden under little covers right next to the windscreen - look at the dash from outside the car through the screen to see them. The cogs you need unfortunately only come in a kit which costs around £40 from MB. Worth changing some of the other cogs/lever arms while you are in there.

A good thread is here-

Noisy Air Conditioner ?? Stepper Motor Replacement / Clicking & Hissing - MBWorld.org Forums

Let me know if you need any more info.

Cheers guy.

Have the top dash out now and can see nearly all the steppers.

 

[Coruscator]

I can see which motor it is now I can feel and hear it clicking. I looks like it is in one hell of a place to get to.

I'm gonna need your help here Lecky.

I can see I'll be able to remove the stepper, with difficulty, but If do so
I wont be able to see whats under it.

Can you talk me through it?

I had a look at your other post and can see the two offending cogs.

how do you get them out and back in?

Thanks bro, so glad you commented on this thread. :0)

 

[Coruscator]

Look at the state of my Benz :0(

 

[AMGeed]

Hope you don't have a handful of fittings left over when its finally reassembled
That looks a pig of a job!

 

[Lecky]

The manuals say you have to remove the heater box which is a nightmare. I managed to get to the offending stepper motor by unbolting the blower motor housing from the engine bay. Remove the cabin air filter and you will see 4 nuts to remove. Go back to the passenger seat and unbolt the big nut holding the metal frame on the left hand side near the blower housing. You should then be able to pull and prise the housing down far enough to get access to the stepper. It's not a lot but just enough. I use a ratchet ring spanner with adapter to the torx bit (T20 I think). Three torx screws on the stepper and it then lifts out. One round cog should be attached to the stepper and the other plastic cog should be in the hole. All this done by feel!!

If your gogs look fine its probable the stepper itself causing the problem however they seem pretty strong to me.

The bits you need will be in a kit from MB as explained previously. The first time I did this the cogs had shattered probably due to age. The second time the cog teeth had worn on the edges suggesting an alignment problem - it lasted a couple of years. Some of the forums suggest replacing the heater box to cure this but I couldn't justify the hassle / cost.

I plugged in my A/C panel while it was all apart and carried out the resync process to check the other motors.

I only had two screws left over so not too bad. Good effort so far. Good luck

 

[Lecky]

Here's a close up of how what should be below the motor:-



When you are putting it back together, make sure the charcoal filter flap moves freely and isnt sticking. refit the stepper screws and tighten carefully a little at a time keeping the motor in position so it doesn't get distorted.

Its a great feeling when its all back together and that annoying snapping noise has gone. Also expect to have to reset the airbag light.

 

[Coruscator]

Here's a close up of how what should be below the motor:-

View attachment 57751

When you are putting it back together, make sure the charcoal filter flap moves freely and isnt sticking. refit the stepper screws and tighten carefully a little at a time keeping the motor in position so it doesn't get distorted.

Its a great feeling when its all back together and that annoying snapping noise has gone. Also expect to have to reset the airbag light.

Oh man that photo is awesome! Tells me so much info!

Ive almost got the stepper off without dropping the blower housing. But I think I'm gonna have to drop it to be able to get it back on.

I notice that the cog thats connected to the flap has two splines in its shaft. Does this just pull up and out after Ive removed the stepper?

Im gonna want to inspect it for damage.

Thanks bro your a star!!!

 

[Lecky]

Yes it just pulls up and out. You can only fit it in one position so no worries about it not being in the correct position. I took that photo when I was investigating possible alignment issues.

 

[Coruscator]

Oh no. :0(

Stepper off now.

It looks as though the shaft has snapped off the cog.

This is going to be a nightmare isnt it?


I'm not sure if my cogs look the same as yours.

What do you think?

 

[Lecky]

Yes looks like the shaft has snapped. You should be able to fish it out with something or try and stick something onto it then pull it out.