H. Vacuum Function Diagram For Controlling Main Air Flap
Air flow switch (4) in position "0", main air flap closed, no fresh air supply
4 Air flow switch
30 Vacuum connection at intake pipe
31 Non-return valve
32 Vacuum reservoir
33 Vacuum element for main air flap, left
34 Vacuum element for main air flap, right
Color identification of vacuum line
gr = gray rt/gr = red/gray
rt = red rt/gb = red/green
Air flow switch (4) moved from position "0", main air flap open, fresh air supply with or without blower assistance