c320 HVAC Stepper Motor/Linkage or more?
Thread Starter
Newbie
Joined: Jun 2010
Posts: 6
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03 325i - 01 C320
c320 HVAC Stepper Motor/Linkage or more?
I just recently purchased a 2001 C320 for my wife that suffers from only receiving cold air from the footwell vents. When the temperature is increased, the air still blows cold. When the air distribution is adjusted, nothing happens at all. I don't hear any kind of clicking sound at all (or anything for that matter). I've tried the defrost+recirc reset and it just keeps on running.
Am I looking at an issue with just the stepper motors? Or is something else going on here? Everything I've read in regards to the stepper motors never mentions anything about not being able to get a temperature change, yet I see that there are motors that adjust the hot/cold air mixture.
Any ideas? I plan on ripping the interior apart tonight. I'm debating whether I should stop by the dealer on the way home to pick up their 2 linkage packages they have on hand...
edit: no difference from driver to passenger side.
Am I looking at an issue with just the stepper motors? Or is something else going on here? Everything I've read in regards to the stepper motors never mentions anything about not being able to get a temperature change, yet I see that there are motors that adjust the hot/cold air mixture.
Any ideas? I plan on ripping the interior apart tonight. I'm debating whether I should stop by the dealer on the way home to pick up their 2 linkage packages they have on hand...
edit: no difference from driver to passenger side.
Member
Joined: May 2007
Posts: 93
Likes: 3
From: Chicago
08 E350 4MATIC
What happens when you re-sync the HVAC system?
Does the system switch between cold and warm during the process?
Can you describe the outside ambient temperature, what happens when the temp dials are cranked to full heat, and do you have a sunroof that is open?
I replaced my own footwell lever and I know the HVAC system temp controls
act differently when the sunroof is open and the temps are lower.
Does the system switch between cold and warm during the process?
Can you describe the outside ambient temperature, what happens when the temp dials are cranked to full heat, and do you have a sunroof that is open?
I replaced my own footwell lever and I know the HVAC system temp controls
act differently when the sunroof is open and the temps are lower.
Super Member
Joined: Jun 2005
Posts: 651
Likes: 5
From: So. Cal.
'02 C320 Wagon, '78 308 GTS, '06 Highlander Hybrid
I just recently purchased a 2001 C320 for my wife that suffers from only receiving cold air from the footwell vents. When the temperature is increased, the air still blows cold. When the air distribution is adjusted, nothing happens at all. I don't hear any kind of clicking sound at all (or anything for that matter). I've tried the defrost+recirc reset and it just keeps on running.
Am I looking at an issue with just the stepper motors? Or is something else going on here? Everything I've read in regards to the stepper motors never mentions anything about not being able to get a temperature change, yet I see that there are motors that adjust the hot/cold air mixture.
Any ideas? I plan on ripping the interior apart tonight. I'm debating whether I should stop by the dealer on the way home to pick up their 2 linkage packages they have on hand...
edit: no difference from driver to passenger side.
Am I looking at an issue with just the stepper motors? Or is something else going on here? Everything I've read in regards to the stepper motors never mentions anything about not being able to get a temperature change, yet I see that there are motors that adjust the hot/cold air mixture.
Any ideas? I plan on ripping the interior apart tonight. I'm debating whether I should stop by the dealer on the way home to pick up their 2 linkage packages they have on hand...
edit: no difference from driver to passenger side.
Member
Joined: May 2007
Posts: 93
Likes: 3
From: Chicago
08 E350 4MATIC
Are all vents open at once possible?
I just don't see this happening unless there are that many broken HVAC levers...
When I switch to economy mode, I notice 'conditioned' air for a good 5-10 minutes as well - I believe this expected behavior.
Anybody else have ideas? *cough Glyn cough*
I just don't see this happening unless there are that many broken HVAC levers...
When I switch to economy mode, I notice 'conditioned' air for a good 5-10 minutes as well - I believe this expected behavior.
Anybody else have ideas? *cough Glyn cough*
Thread Starter
Newbie
Joined: Jun 2010
Posts: 6
Likes: 0
03 325i - 01 C320
What happens when you re-sync the HVAC system?
Does the system switch between cold and warm during the process?
Can you describe the outside ambient temperature, what happens when the temp dials are cranked to full heat, and do you have a sunroof that is open?
I replaced my own footwell lever and I know the HVAC system temp controls
act differently when the sunroof is open and the temps are lower.
Does the system switch between cold and warm during the process?
Can you describe the outside ambient temperature, what happens when the temp dials are cranked to full heat, and do you have a sunroof that is open?
I replaced my own footwell lever and I know the HVAC system temp controls
act differently when the sunroof is open and the temps are lower.
I've tried cranking it to full heat during the cooler night temperaturs (~50 degrees) and still no warm air. I've never tried with the sunroof open.
Air just comes out in the footwells, and it's always cold.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
When re-syncing, nothing happens at all. No change in temp, air distribution, nothing.
I've tried cranking it to full heat during the cooler night temperaturs (~50 degrees) and still no warm air. I've never tried with the sunroof open.
Air just comes out in the footwells, and it's always cold.
I've tried cranking it to full heat during the cooler night temperaturs (~50 degrees) and still no warm air. I've never tried with the sunroof open.
Air just comes out in the footwells, and it's always cold.
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Thread Starter
Newbie
Joined: Jun 2010
Posts: 6
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03 325i - 01 C320
If the re sync continues forever without stopping then that's an indication that something is wrong with the stepper motor(s)/flap(s). Just from your symptom though it sounds like you have the classic broken linkages. There's a good DIY writeup in this forum to help you through the R&R process.
That's what I'm thinking too. Would it be safe to buy a single 3-pack of linkage arms from the dealer or should I buy more? What about the motors themselves?
I've read there's a valve in the engine compartment that regulates the flow of coolant through the heater core, I was just concerned that there may be an issue there due to the lack of warm air...
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Super Member
Joined: Jun 2005
Posts: 651
Likes: 5
From: So. Cal.
'02 C320 Wagon, '78 308 GTS, '06 Highlander Hybrid
If the re sync continues forever without stopping then that's an indication that something is wrong with the stepper motor(s)/flap(s). Just from your symptom though it sounds like you have the classic broken linkages. There's a good DIY writeup in this forum to help you through the R&R process.
Thanks
MBWorld Fanatic!
Joined: Jan 2006
Posts: 3,212
Likes: 8
From: Pasadena, CA
2002 C230K, 2013 BMW 328, 2015 BMW X5
I'm right there with you.
I get my A/C to all of the vents and particularly to the footwells.
I'm going to follow along on this. Though having just taken apart and repaired the console and the arm rest, I'm in no rush to get into the dash.
Ed
I get my A/C to all of the vents and particularly to the footwells.
I'm going to follow along on this. Though having just taken apart and repaired the console and the arm rest, I'm in no rush to get into the dash.
Ed
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
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From: Huntington Beach, Ca.
'17 Jaguar XF
https://mbworld.org/forums/c-class-w...ost-works.html
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MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
Could be, but I haven't heard of one actually going out yet. You'll need to address the stepper motor/linkage problem first anyway.
Thread Starter
Newbie
Joined: Jun 2010
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03 325i - 01 C320
UPDATE: I finally ripped apart the dash to find a single actuator arm broken. It was the arm on the right footwell motor. This arm being broken caused the entire HVAC system to lose all adjustability, including temperature regulation and air distribution.
Hopefully this will help someone else now or in the future.
Thanks for all the replies everyone.
Hopefully this will help someone else now or in the future.
Thanks for all the replies everyone.
Thread Starter
Newbie
Joined: Jun 2010
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03 325i - 01 C320
Newbie
Joined: Apr 2011
Posts: 1
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1996 suburban
My inlaws have a 2003 c240 with the common ticking noise in dash, after cussing MB I finally found that the mode actuator was the culprit. Looking up throuh the floor vent with a flashlight I can see the flaps moving going from floor to i think upper vents and back to the floor before the noise starts. My question is can resyncing the actuators help this concern or will replacement be necessary. Any help would be greatly appreciated
