2001 c320 AC/Heater vents not working.
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Joined: Aug 2022
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2001 c320
2001 c320 AC/Heater vents not working.
I’ve tried everything I can think of. Here’s how my AC/Heater is currently working.
blow hot
blows cold
no air flow to the rear center console vents
little are flow to both front passenger vents
strong air flow to driver vents
drive foot vent is always open
my issue is no air flow to rear. This Texas heat is cooking my kids in the back seat.
I checked all filter, the blower motor is perfect, Took the glovebox off and check the flaps and they seem to work. I even did the system check by holding the defrost and circulate button (keeps on blinking until I turn car off.
im stuck, need some help/advise/tips! Please!
how and where are the air ducks for the rear vents?
blow hot
blows cold
no air flow to the rear center console vents
little are flow to both front passenger vents
strong air flow to driver vents
drive foot vent is always open
my issue is no air flow to rear. This Texas heat is cooking my kids in the back seat.
I checked all filter, the blower motor is perfect, Took the glovebox off and check the flaps and they seem to work. I even did the system check by holding the defrost and circulate button (keeps on blinking until I turn car off.
im stuck, need some help/advise/tips! Please!
how and where are the air ducks for the rear vents?
MBWorld Fanatic!
Joined: Dec 2003
Posts: 3,275
Likes: 236
From: BC, Canada
2003 C230K Coupe Orion Blue
The system recalibrate you mentioned (holding down the defrost and recirculation buttons) needs to run for 2 minutes or so before the lights stop blinking. If they stay blinking, there is a problem. I heard the car needs to be turned off for at least 40 seconds to store the new values, but you're probably doing that already.
Are you the first owner of the car?
There are no dampers between front and rear so to speak. When the air is directed to the front footwells, there is also airflow to the feet of the rear passengers. The outlet is underneath the front seats. When air is directed to the faces of the front passengers, there is also airflow to the vent above the rear ashtray.
I assume the airflow wheel to the rear vent is open? Yes it's a dumb question, but I have to ask.
If everything is in order there (check everything above first), then I would look into the HVAC stepper motor issue. You may have broken motors or linkages. These linkages have basically a 100% failure rate, which is why I'm asking if you are the original owner of the car. The motors also like to fail (the internal gear teeth will strip). Replacing a motor or linkage is quite the involved process, so if you are going to tear up the dashboard, the bare minimum is to update most of the linkages (MB sells a beefed up kit for the linkages that fail the most often), followed by replacing any of a handful of motors because of the amount of work required. FYI the footwell ones like to fail first for some reason. Both the linkages and the footwell motor failed for me, but I would definitely check everything if the dash is opened up.
Are you the first owner of the car?
There are no dampers between front and rear so to speak. When the air is directed to the front footwells, there is also airflow to the feet of the rear passengers. The outlet is underneath the front seats. When air is directed to the faces of the front passengers, there is also airflow to the vent above the rear ashtray.
I assume the airflow wheel to the rear vent is open? Yes it's a dumb question, but I have to ask.
If everything is in order there (check everything above first), then I would look into the HVAC stepper motor issue. You may have broken motors or linkages. These linkages have basically a 100% failure rate, which is why I'm asking if you are the original owner of the car. The motors also like to fail (the internal gear teeth will strip). Replacing a motor or linkage is quite the involved process, so if you are going to tear up the dashboard, the bare minimum is to update most of the linkages (MB sells a beefed up kit for the linkages that fail the most often), followed by replacing any of a handful of motors because of the amount of work required. FYI the footwell ones like to fail first for some reason. Both the linkages and the footwell motor failed for me, but I would definitely check everything if the dash is opened up.
Last edited by slammer111; Aug 17, 2022 at 06:55 PM.
