Cadillac 60 Series 1963 Shop Manual page 399

13-18
HEATING AND AIR CONDITIONING
Selector Lever Vacuum Valve
Fast Idle Vacuum
Power Unit
Water Control Valve
Vacuum Power Unit
Purple
Green
Blue
Suction Throttle Valve Vacuum Power Unit
20%-100% Vacuum Power Unit
Outside Air Nipples
Vacuum Check Valve
On Dash Insulator
Heater-Air Conditioner Assembly
^Black
N R e d
Temperature Lever Vacuum Valve
Selector Lever Vacuum Valve
Air Conditioner-Heater Control Panel
Heater-Air Conditioner
Vacuum Power Unit
Fig. 13-16 Heater and Air Conditioner Vacuum Circuit (OFF Position) 60 and 62 Series
As the selector lever is moved to the "Cool"
position, vacuum is applied to the 20%-100%
vacuum diaphragm through both vacuum lines,
and to the heater-Air Conditioner vacuum dia-
phragm. The air inlet valve opens, admitting
outside air into the system; and the heater-Air
Conditioner valve and diverter valve move to the
Air Conditioner position, Fig. 13-18. Simultane-
ously, the electrical circuit to the blower and
compressor is completed, putting them in opera-
tion.
Moving the selector lever to "Recirc" cuts
off the vacuum to one of the two vacuum lines to
the 20%-100% diaphragm. The air inlet valve
then moves to the recirculate position, so that
80% of the air being drawn through the blower
comes from the passenger compartment, Fig.
13-18, for maximum cooling action.
The temperature (lower) lever controls the
temperature valve located in the heater-Air Cond-
itioner assembly, Fig. 13-18, by means of a bow-
den cable. Moving the temperature lever to the
left correspondingly reduces the amount of air
passing through the heater core that is allowed
to mix with the cooled air flowing from the eva-
porator. With the lever in the "Cooler" position,
the temperature valve prevents any heated air
from mixing with the cooled air.
When the temperature lever reaches a point
approximately 3/4 inch from the end of its travel
to the "Cooler" position, it applies vacuum to
the suction throttling valve, increasing the cooling
capacity of the evaporator. At the same time,
vacuum to the engine-mounted water control valve
is cut off, preventing loss of cooling by heat con-
duction within the heater-Air Conditioner assem-
bly.
Operation (75 Series)
With the selector (upper) lever in the "Off"
position, the air inlet valve is closed, and the
heater-Air Conditioner valve is in the heater
position, Fig. 13-17.
When the selector lever is moved to the "Cool"
position, vacuum is applied to the 20% diaphragm,
the 100% diaphragm and the heater-Air Condi-
tioner diaphragm. The air inlet valve opens,
allowing outside air to enter the blower housing,
and the heater-Air Conditioner valve moves to the
Air Conditioner position, Fig. 13-19. Simultane-
ously, the electrical circuit to the blower and
compressor are completed.
Moving the selector lever to the "Recirc"
position cuts off vacuum to the 100% diaphragm.
The 20% diaphragm holds the air inlet valve par-
tially open, Fig. 13-19, so that 80% of the air
being drawn through the blower comes from the
passenger compartment, providing maximum cool-
ing action.