03 S500. Wondering where to look to get full airflow from all vents....
Center vents, full speed and work fine
the outer vents (by the doors) very weak air flow.

The airflow is adjustable. The small handwheel at each vent can adjust flow from none to full, with the bar in the center of the adjustment level setting "auto", or computer control. If that doesn't work, you will need to get the car on SDS, where you can test each of the airflow actuators.

The "Owners Handbook" is actually a good 6" of reading material. There will be quite a few surprises in there...

If you don't have the books, free downloads are available on-line.

thank you captain obvious. they are all set to fully open this isnt my first car.
your unhelpful sarcasm is noted.

sheesh, i miss the helpfulness of bmw community. its def not the same in the benz world

A$$hole newbie!! (joined 2011???)
Go away!

Wally gave you a detailed helpful answer

you won’t be getting any other help here better find your own solutions

My apologies for not recognizing your outstanding level of knowledge and experience from your simple question. I'm not really certain what part of a serious answer struck you as sarcasm - but I can assure you that it won't happen again.

Captain Obvious, AKA

thanks for proving my statement as fact

wasnt getting any to begin with, so obviously no different. funny how theres more responses on this than there are actual discussions. i stand by my statement as "RTFM" mentality isnt useful.

your answer consisted of reading the manual and opening the vents, as if those extremely obvious things to check wouldnt be done already.

I have the same problem.

It's something to do with the flaps; they will blow full power in diagnostic mode when the center vents are off. It's just the center vents are off entirely when that happens. I'd settle for equal airflow blowing from all vents but I don't know how to manually adjust these flaps, it's either open or closed.