a) Up to 08/83

Air volume slide switch in position "min", fresh air/recirculated air flap closed - no fresh air supply

1st version
A Vacuum output
B Positive ventilation
E Vacuum input
1 Air volume slide switch with vacuum switch
18 Switch-over valve for fresh air/recirculated air flap
30 Vacuum connection on intake manifold
31 Check valve
33 2-stage vacuum element for fresh air/recirculated air flap
34 Evaporator housing
a Connection to left-hand heater switch for vacuum water valve

Arrow, white Fresh air
Arrow, black Recirculated air







Air volume slide switch at 1st blower stage, fresh air/recirculated air flap open, 100% fresh air

1st version
A Vacuum output
B Positive ventilation
E Vacuum input
1 Air volume slide switch with vacuum switch
18 Switch-over valve for fresh air/recirculated air flap
30 Vacuum connection on intake manifold
31 Check, valve
33 2-stage vacuum element for fresh air/recirculated air flap
34 Evaporator housing
a Connection to left-hand heater switch for vacuum water valve

Arrow, white Fresh air
Arrow, black Recirculated air







Air volume slide switch at 1st blower stage, and fresh recirculated air switch switched on, fresh air/recirculated air flap in position "recirculated air" corresponds to approx. 20% fresh air and 80% recirculated air

1st version
A Vacuum output
B Positive ventilation
E Vacuum input
1 Air volume slide switch with vacuum switch
18 Switch-over valve for fresh air/recirculated air flap
30 Vacuum connection on intake manifold
31 check valve
33 2-stage vacuum element for fresh air/recirculated air flap
34 Evaporator housing
a Connection to left-hand heater switch for vacuum water valve

Arrow, white Fresh air
Arrow, black Recirculated air