Air Conditioning Blowing Little To No Air Out
08-16-2023, 09:08 PM
#1
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Air Conditioning Blowing Little To No Air Out
Hi MBWorld Members.
I own a Mercedez Benz C240 (W203) and notice a clicking sound when I start the car (runs for a minute or so) believed to becoming from the aircon system. The aircon works however there is little to no air coming out of the vents. I did some digging and read about an aircon ac actuator being broken and that is all to be replaced to make the ac work again. Can anyone confirm this? If so where do I get the part from and can it be done as a DIY or need some serious expert to complete the job. If the actuator is not the problem how can I diagnose and solve this problem. Appreciate any help, summer is kicking my backside soon!
I own a Mercedez Benz C240 (W203) and notice a clicking sound when I start the car (runs for a minute or so) believed to becoming from the aircon system. The aircon works however there is little to no air coming out of the vents. I did some digging and read about an aircon ac actuator being broken and that is all to be replaced to make the ac work again. Can anyone confirm this? If so where do I get the part from and can it be done as a DIY or need some serious expert to complete the job. If the actuator is not the problem how can I diagnose and solve this problem. Appreciate any help, summer is kicking my backside soon!
08-16-2023, 09:36 PM
#2
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2003 C230K Coupe Orion Blue
You have the infamous HVAC stepper motor problem. Based on your description, you probably have a failed linkage, but this isn't guaranteed. It could be a bad motor as well - the internal gears are known for stripping, at least on the old version of the motors.
There are instructions on how to fix the thing buried in here somewhere. Someone made a 3 page PDF as well.
This repair is painful because of the amount of stuff to remove. Instructions are in the PDF.
If you haven't done so, also replace the footwell linkages with the updated (thicker) version. Dealer will have them.
Keep in mind that you may have more than 1 broken motor or linkage. You'll have to open up the dash to find out what's broken. But definitely update all the linkages while everything is opened up.
To test the system, push and hold the front defrost and recirculation buttons (ie the first 2 buttons) for a few seconds and the lights on the buttons will start flashing and the car will cycle and recalibrate every motor. This should help with the diagnosis. At this point, simply follow the source of the clicking and you'll have your answer.
Good luck.
There are instructions on how to fix the thing buried in here somewhere. Someone made a 3 page PDF as well.
This repair is painful because of the amount of stuff to remove. Instructions are in the PDF.
If you haven't done so, also replace the footwell linkages with the updated (thicker) version. Dealer will have them.
Keep in mind that you may have more than 1 broken motor or linkage. You'll have to open up the dash to find out what's broken. But definitely update all the linkages while everything is opened up.
To test the system, push and hold the front defrost and recirculation buttons (ie the first 2 buttons) for a few seconds and the lights on the buttons will start flashing and the car will cycle and recalibrate every motor. This should help with the diagnosis. At this point, simply follow the source of the clicking and you'll have your answer.
Good luck.
Last edited by slammer111; 08-16-2023 at 09:41 PM.
08-16-2023, 09:46 PM
#3
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Thread Starter
Thanks for your help. Will dig up that pdf if you remember where it was may you reply to this 
In terms of testing the system I'm a little confused still on what two buttons to press. Are these on the motors or somewhere else? This is what it currently looks like if it helps. Thanks 
In terms of testing the system I'm a little confused still on what two buttons to press. Are these on the motors or somewhere else? This is what it currently looks like if it helps. Thanks
08-16-2023, 10:15 PM
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2003 C230K Coupe Orion Blue
Best to just read the entire thread so you get a feel of what the job entails. Someone posted it as an attachment. Can't do all the work for you. 
The 2 buttons are in the row of buttons along your HVAC control panel, right above the ashtray space with the flip cover. They're right underneath your dials/buttons for temperature adjustment.
The 2 buttons are in the row of buttons along your HVAC control panel, right above the ashtray space with the flip cover. They're right underneath your dials/buttons for temperature adjustment.
