Can someone tell me how to (and where) to check and see if the "fresh air door" is closing on my 89 300CE?

I have the Mercedes CD and can't seem to get an idea of how to check even if I remove the dash etc like in the diagrams.

Pull the vacuum line from the switchover valve and pull a vacuum on it. If it holds it is probably OK. The fresh air door elements are numbered 42 and the switchover valve assy is y7 and the full stroke switchover is #2.

Attached Thumbnails

 

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thanks Steve. Is that diagram on the Mercedes Service CD? I don't seem to remember it. Perhaps I just skimmed by it.

Thanks

Maybe a little bigger.

Attached Thumbnails

 

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician