On this car I asked about last week, I have it here now for a brake job, looking at OS rear view, like I was asking about.
Center vent won't open, even if I select the vent/heater arrows manually. Side vents open OK. Owner not complaining about it, but it's his first Benz.
When in a low vacuum condition (up hill or hard acceleration) the air then comes out the defroster, until high vacuum returns (coasting, or at least off the throttle). I can't remember if it has a vacuum tank somewhere? I thought I remember something about the PSE assisting in providing extra vacuum at times? Might be a different model. Thought I'd ask quick before I start work on the car. Thanks, will check to see if I get an answer later.

Gilly

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