GMC 1982 Light Duty Truck Service Manual page 49

IB-6 AIR CONDITIONING
S E L E C T O R
L E V E R C O M PR ESSO R
P O S IT IO N
O F F
O F F
M A X A /C O N
N O R M A /C O N
O N
B I - L E V E L
V E N T
O F F
H T R
O F F
D E F
O N
N O T E % 100% Inside air is n o t available, some bleed through o f outside air is allow ed.
V a cu u m Schem atic - C-K Truck
The C-K Truck air conditioning vacuum schematic is
shown in Fig. I B-7.
System O peration - G M odels
System operation is shown in Fig. 1B-8.
V acu u m Schem atic - G M odels
G Model vacuum schematic is shown in Fig. 1 B-9.
O VER H E A D SYSTEM (C-K & G SERIES)
This system o perates in conjunction with the C60
system. Since refrigerant flow is controlled by the front
system, the only control provided for on the overhead system
is a three-speed fan switch (LO W , MED, HI). The fan
S Y S T E M O P E R A T IO N - C K T R U C K
B LO W ER
A IR
SPEEDS
SO U R C E
A V A I L
LO W O U T S ID E
HI IN S I D E %
O U T S ID E
A L L
A L L O U T S ID E
A L L O U T S ID E
A L L O U T S ID E
O U T S ID E
A L L
Fig. 1 B-6-System Operation - C-K Truck
Fig. 1 B-7—Air Conditioning Vacuum Schematic - C-K Truck
A IR
E N T E R S
V E H IC L E
F L O O R O U T L E T S
D A S H O U T L E T S
D A S H O U T L E T S
F L O O R A N D
D A S H O U T L E T S
D A S H O U T L E T S
F L O O R O U T L E T S
D E F R O S T O U T L E T S
switch is mounted in the instrument panel, to the right of the
steering coloumn (Fig. 1 B -10).
In the O F F position, the blower is inoperative;
however, refrigerant is circulating in the system if the C60
System is O N . In any of the three blower positions (LOW ,
MED, HI), the blower will be operative regardless if the
Four-Season system is O N .
To obtain maximum cooling, the Four-Season System
should be on A /C , tem perature lever on CO LD, blower
switch on HI and the overhead unit blower switch should be
on HI.
O VER H EA D SYSTEM (G MODELS)
This system operates in conjunction with the C60
system. Since refrigerant is controlled by the C60 system,
the only control provided on the rear overhead system is a
H E A T E R A /C H E A T E R
D O O R - D E F R O S T E R
OPEN TO: D O O R - O P E N TO:
H E A T E R H E A T E R
A /C H E A T E R
H E A T E R
A /C
A /C &
H E A T E R
H E A T E R
A /C H E A T E R
H E A T E R H E A T E R
H E A T E R D E F R O S T