Low blow

[outsmartsmart]

2004 E320CDi, with the mini heatwave the aircon is being used extensively. When set to cabin vents the two central ones only give a trickle of air even when cranked up fully (yes I have them 'open' ).

The outer two are the veritable 'hairdryer' type rush but the central two are just like 'natural ram air' at most.

I'm guessing either a paddle/valve isn't opening or in, old fashioned parlance, a pipe is kinked somewhere. Not easy to check as all enclosed but any clues where to look please?

 

[Cole@MBS]

The flaps are controlled by stepper motors, needs a star really to see what the values of the motors are!!

 

[carabind]

Ive noticed similar, though I do get a decent flow through the middle vents, the air rate does differ from central and side.

 

[PanzerMcGrory]

mines is the same in all modes exept when i select those specific vents.