Cadillac 60 Series 1963 Shop Manual page 400

HEATING AND AIR CONDITIONING
13-19
Vacuum Check Valve
On Dash Insulator
Yellow
Black
Selector Lever
Vacuum Valve
Fast Idle
Vacuum Power
e
^ / ^ b S ^ Black
20% Vacuum
Power Unit**
Purple «•
\ /
_ ^
Vacuum Power Unit —
100% Vacuum
dh_ Power Unit
T
G r e e n
LK\
II' 1 1 •
# Air From Outside
T
y Passenger
A j r F r o m
Compartment
C
owi Vent
I
Suction
Throttling
— Valve
-v ^HL Red
^ ^ Air Conditioner
>/Vacuum Power Unit
i
i ^Purple
r
o Heater
To Evaporator
Suction Throttle Valve
Vacuum Modulator
Vacuum Modulator-
Air Conditioner-Heater Control Panel
Suction Throttling Valve Vacuum Power Unit
Fig. 13-17 Heater and Air Conditioner Vacuum Circuit (OFF Position) - 75 Series
The control knob for admitting outside air to
the rear evaporator unit is located on the rear
shelf panel. With the knob in the "Off" position,
the rear blowers deliver 100% recirculated air
into the passenger compartment. Outside air is
admitted into the system by turning the knob
counterclockwise. Moving the rear fan control
knob from the "Off" position completes the elec-
trical circuit to the compressor.
The temperature controls are equipped with
vacuum modulators that regulate the suction throt-
tling valve, thereby controlling the discharge air
temperature. Moving the controls toward the
"Cooler" position reduces the vacuum to the
suction throttling valve, increasing the cooling
capacities of the evaporator.
Electrical Circuit
(Fig. 13-20, 2 1 , and 22)
The Air Conditioner electrical circuit current
flows from the accessory terminal of the ignition
switch to the 25 ampere fuse in the fuse block.
The current then flows to the heater-Air Condi-
tioner control switch, which controls the com-
pressor circuit and provides a feed for the Air
Conditioner blower switch. The heater-Air Condi-
tioner control switch also provides a feed to the
blower resistor so that at any time the system is
turned on, the blower will operate at the speed
for which the blower switch is set. This is ac-
complished by by-passing segments of the blower
resistor for each higher speed.
A separate feed circuit from the 25 ampere fuse
is provided for 75 series cars with the additional
cooling unit in the rear. A two wire circuit, com-
posed of a feed and a compressor control, runs
to the rear seat right hand arm rest control panel.
This panel has* a switch to control the three speeds
of the two rear unit blowers, and to control the
compressor.