Porsche 928 S 1986 Driver Manual page 42

Auxiliary evaporator for increased
refrigeration
In vehicles with increased refrigeration, the
rear storage compartment is replaced by an
additional evaporator with a blower.
With the air conditioner on (AC switch pressed)
the rear evaporator can be switched on by
turning the left-hand knob in the centre con-
sole to the right. The blower speed is controlled
between speeds 1 and 3.
38
The output of the rear evaporator is increased
by turning the right-hand knob to the right.
The passenger compartment air is drawn in
through the rear grille, cooled and distributed
through the grilles in the rear. If the AC switch
is not pressed, there is only a recirculation of
the air.