Noisy Air Conditioner ?? Stepper Motor Replacement / Clicking & Hissing
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Joined: Apr 2007
Posts: 27
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From: Annapolis, MD
2002 C240
Step #17...
Additional comments for step....
After you replace the new linkage connect the wires back to the radio trim. Turn the ignition on and resync the stepper motors. I made the mistake in putting the dash back together to find out I had a linkage broken and a stepper motor broken as well. I had to go back into the dash to find and replace it.
Additional comments for step....
After you replace the new linkage connect the wires back to the radio trim. Turn the ignition on and resync the stepper motors. I made the mistake in putting the dash back together to find out I had a linkage broken and a stepper motor broken as well. I had to go back into the dash to find and replace it.
Last edited by liveniceguy; May 22, 2007 at 05:02 PM. Reason: Added txt.
Newbie
Joined: Oct 2006
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From: Kansas City, MO
01 C320
I am getting ready to replace my lower foot panal flaps but I have a question. I have a 01 C320 and when I move the **** to change the direction of the air flow I dont hear anything like its trying to redirect it. would that be my actual climate controll device that you use to adjust is not working? also when I hear the clicking sound it doesnt sound like it is comeing from were the lower foot panal flaps are, it sounds like it is right behind the center vents, but the air always goes to the floor. thanks for your help.
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Newbie
Joined: Oct 2006
Posts: 18
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From: Kansas City, MO
01 C320
Does anyone know which stepper moter, and or linkage would be making the clicking sound behind the center vent? It doesnt blow air out of it, pretty much nothing but some air. I replaced the left footwell flap and one close to the glove compartment using the same linkage that I used for the left footwell flap. The ones that where in the center looked different as far as linkage. any input would greatly appreciated. thanks
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Joined: Apr 2007
Posts: 27
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From: Annapolis, MD
2002 C240
Mattty,
Sounds like the same area that mine was. There are two behind the radio/ ignition switch. Just gotta pull it apart and test them once apart. I had a bad motor and a bad linkage.
Sounds like the same area that mine was. There are two behind the radio/ ignition switch. Just gotta pull it apart and test them once apart. I had a bad motor and a bad linkage.
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Joined: Jun 2005
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From: Mililani, Hawaii
2005 SLK 350 w AMG / 2008 C / 2019 A220
Junior Member
Joined: Jun 2005
Posts: 46
Likes: 0
From: Mililani, Hawaii
2005 SLK 350 w AMG / 2008 C / 2019 A220
I have a 2003 C240 and I just completed the linkage repair for the left footwell. Without Racin_Fool's detailed instructions and liveniceguy's pictures, this would have been impossible. 
Everything went fairly smoothly. Did have a problem removing the plastic cage that holds the radio/ac cluster. Maybe I was missing something but we just couldn't get it out. We eventually were able to remove it and continue the process. When I initially removed the linkage I didn't see a break. After a closer look, I noticed a hairline crack running the entire depth of the part where it connects to the stepper motor. Hooked up the new piece, reattached the stepper motor, and re-connected the wiring to the a/c control. Turned the ignition to the 'on' position. Didn't see any movement in the linkage. It then dawned on me that I needed to re-sync the vents. Ran through the sync process and I saw the linkage move and I didn't hear any clicking! YES! Just saved over $700.
I am now getting air out of the left footwell vent when I want it. Before it was hit or miss.
Once again, a big MAHALO goes out to Racin_Fool and liveniceguy.
The whole process took a little longer than I expected. This may have been because the wife was supervising every step.
When we had the radio/ac cluster out, I noticed a second firber optic cable that said radio in. Does anyone know what this is for?????
Everything went fairly smoothly. Did have a problem removing the plastic cage that holds the radio/ac cluster. Maybe I was missing something but we just couldn't get it out. We eventually were able to remove it and continue the process. When I initially removed the linkage I didn't see a break. After a closer look, I noticed a hairline crack running the entire depth of the part where it connects to the stepper motor. Hooked up the new piece, reattached the stepper motor, and re-connected the wiring to the a/c control. Turned the ignition to the 'on' position. Didn't see any movement in the linkage. It then dawned on me that I needed to re-sync the vents. Ran through the sync process and I saw the linkage move and I didn't hear any clicking! YES! Just saved over $700.
I am now getting air out of the left footwell vent when I want it. Before it was hit or miss.
Once again, a big MAHALO goes out to Racin_Fool and liveniceguy.
The whole process took a little longer than I expected. This may have been because the wife was supervising every step.
When we had the radio/ac cluster out, I noticed a second firber optic cable that said radio in. Does anyone know what this is for?????
Last edited by hebsan; Aug 5, 2007 at 02:40 AM.
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Joined: Nov 2001
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From: Huntington Beach, Ca.
'17 Jaguar XF
I had the same problem. Took me longer to get the cage out than doing the rest of it! Ended up forcing it and cracking one of ears on the cage but since it screws in there was no problem.
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From: Norcal, 40 miles from the bay
2002 C230K, 2006 VZ800
EXELLENT!!!!!!!!!!!!!! I love the do it your self, save money attitude. Just because we have benzes does not mean we let other people work on the car and pay them. D I Y S and save $$$$ for......
MODS
But no this thead has helped me out. Thanks guys. And thanks for the pictures.
Rommel
MODS
But no this thead has helped me out. Thanks guys. And thanks for the pictures.
Rommel
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Joined: Feb 2007
Posts: 17
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From: Chilliwack, BC, Canada
2007 GL450, 2007 335i with a Cobb tune (435HP)
Thanks a ton for this tutorial! What a great feeling of satisfaction doing this myself. The pictures were an immense help and thanks for taking the time to be so thorough.
I actually bought both the stepper motor and the actuator arm, even though it only ended up being the arm that was broken. I figured for the 120 bucks CDN that it cost me it was worth it to have the motor just in case (would suck to be stuck in need of it with my dash and centre console strewn all over my garage floor! If anyone needs stepper motor let me know.
Again, thanks.
I actually bought both the stepper motor and the actuator arm, even though it only ended up being the arm that was broken. I figured for the 120 bucks CDN that it cost me it was worth it to have the motor just in case (would suck to be stuck in need of it with my dash and centre console strewn all over my garage floor! If anyone needs stepper motor let me know.
Again, thanks.
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Joined: Jul 2007
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Big Thanks Racin Fool for write up and To LIVENICEGUY for awesome pictures and hints (like where i pry at my ignition for 10 min then i read i have to turn the bezel)
I too completed my linkage swap to find out i had to replace a stepper motor after sync failed during my maiden voyage
My stepper motor would not stop turning (M2/15). If i sync'd the vents the one motor would click til i turned off the ignition. I removed dash again and swapped 2 motors and same motor refused to stop turning, clicking noise was from inside motor actually a feature of the stepper motor (like a clutch) to prevent stripping internal gears.
Also if ur stepper motor needs replaced make sure you align the gears properly! (found out the hard way) Don't worry, 3rd was a cinch!
I have to assume you don't have a cd changer in your glove box. Spare Fiber optic wire is included to install cd changer. I used it to install my cd changer
I too completed my linkage swap to find out i had to replace a stepper motor after sync failed during my maiden voyage
My stepper motor would not stop turning (M2/15). If i sync'd the vents the one motor would click til i turned off the ignition. I removed dash again and swapped 2 motors and same motor refused to stop turning, clicking noise was from inside motor actually a feature of the stepper motor (like a clutch) to prevent stripping internal gears. Also if ur stepper motor needs replaced make sure you align the gears properly! (found out the hard way) Don't worry, 3rd was a cinch!
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From: Mililani, Hawaii
2005 SLK 350 w AMG / 2008 C / 2019 A220
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From: NPR florida
C230k coupe 500sec convertible
sorry for digging up this old thread, but this DIY rocks!! I found it by looking for a Hissing sound issue
One question though, I have the hissing, which is the low freon thing----dealership wants $150 to evac and fill+ find leak(if there) how many lbs would i need realistically and at what pressure should it be at???
One question though, I have the hissing, which is the low freon thing----dealership wants $150 to evac and fill+ find leak(if there) how many lbs would i need realistically and at what pressure should it be at???
Thread Starter
Senior Member
Joined: Sep 2002
Posts: 352
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From: Worcester, MA
15' CLS400
awww ohh.
Yes, the hissing sound means its out. However, I had MB fill it and put in the dye. They didn't find the leak... two months later it ran out again and I paid another $200 to fill it again. They say they can't find the leak and that it is probably a leak in the evaporator core.
I found through some of these threads that evap cores are known to go bad.... and they cost $$$$$$$$$$$$ !! MB want's around $2000 for the 12 hour job plus the part. I'm not willing to pay them that.
... So my conclusion so far. My brother is a mechanic and can get the evap core for $250.00. We're going to put it in ourselves over a weekend. I'll let all know how it goes and how long it really takes.
To answer your question about the lbs, I believe the C-class takes 1.8 lbs. If you look under your hood
to the back left side there is a sticker on the cabin filter box that states the amount.
I found through some of these threads that evap cores are known to go bad.... and they cost $$$$$$$$$$$$ !! MB want's around $2000 for the 12 hour job plus the part. I'm not willing to pay them that.
... So my conclusion so far. My brother is a mechanic and can get the evap core for $250.00. We're going to put it in ourselves over a weekend. I'll let all know how it goes and how long it really takes.
To answer your question about the lbs, I believe the C-class takes 1.8 lbs. If you look under your hood
to the back left side there is a sticker on the cabin filter box that states the amount.
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From: Dundee, IL
2005 Corvette, 2002 MB C230 Coupe
Thanks to everyone for posting info on this topic! This is going to be a huge help! I don't know about the rest of you but it seems so hard to find good DIY write-ups for the Benz's.
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From: I am in the uk and live near london
2001 c320 avantgaurde metalic black,grey leather
could you email me pictures please to pch.builders@blueyonder.co.uk thanks can you tell me i am in the uk so right hand drive,i take it that the instructions are the same ? thanks again for all this you have put on the forum you have saved me £1000 at my dealers.
Last edited by harrington; Nov 19, 2007 at 11:50 AM.
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Is this the same problem??
I think I have the same problem, but the sound is different. I had turned on the defroster and afterwards I get a clack sound, about one loud clack per 3 seconds. Then it stops. The blower no longer works at the footwell. The sound is coming from behind the radio controls or a little higher. Running the reset button sequence, doesn't help, and the clacking kicks in.
...reason I ask is that I want to be sure to order all the parts needed before tearing in.
This is a great post and thanks for all of the pics and instructions!! This is going to save me at least $500!!
Jakeman
2002 C320 Wagon
...reason I ask is that I want to be sure to order all the parts needed before tearing in.
This is a great post and thanks for all of the pics and instructions!! This is going to save me at least $500!!
Jakeman
2002 C320 Wagon
Thread Starter
Senior Member
Joined: Sep 2002
Posts: 352
Likes: 12
From: Worcester, MA
15' CLS400
Ya, would you believe I have the same problem! I originally posted to this thread way back when about it clicking down below on the floor. That was fixed. Now I have the same exact problem but up top somewhere! Ugggg. Need another post for DIY on the top ones now.
Thread Starter
Senior Member
Joined: Sep 2002
Posts: 352
Likes: 12
From: Worcester, MA
15' CLS400
I am getting the clicking up top by the windshield. Must be the one for the defogger. If I follow these directions will I be able to reach up that far? or is there another way to get at that one? Maybe access through the speaker grill on the top center of the dash? Or will the entire dash need to come off?
