foRRREVerz

Question about the operation of the hvac system in our cars – when running the heater directed to the footwell, do you receive cool air from the center vents? Mine is doing this, and Mercedes service is telling me this is standard operation. It seems illogical to me that it would operate this way.

Car is an '04 C320 4matic.

Can anyone else confirm or deny the proper operation?

Thanks!

DarthBudice

If you have the center dial (blue arrow) between the 2 face vents open, then yes.

foRRREVerz

When the cold weather hit our region, I closed the center dial (no blue arrow)... this cut down on the cold air coming in, but didn't stop the flow of cold air completely.

My service rep is stating that MB does not want driver's falling asleep, and hence pushes cold air through the center vents. I think that's a load of deuce.

govertime

lol, and when your pistons start obscenely knocking and belts are squealing...same reason

acr2001

I'll add that to my mental list of absolutely insane BS I've heard from service advisers.

Do you hear any clicking from behind the dash? Your probably have a bad stepper motor linkage. Do a search... you can cycle the HVAC unit to find out if any are bad.

DarthBudice

Wouldn't be surprised if the center vent unit wasn't re-installed properly.
Took me a couple of tries to get it right the first time I removed mine...