Chevrolet 1977 light duty truck, Service Manual

Page: 59 / 861

S Y S T E M O P E R A T IO N - C K T R U C K
SELECTOR
LEVER
POSITION
COMPRESSOR
BLOWER
SPEEDS
A V A IL
AIR
SOURCE
AIR
ENTERS
VEHICLE
HEATER A/C
DOOR-
OPEN TO:
HEATER
DEFROSTER
D O O R-O PEN TO:
OFF
OFF LOW OUTSIDE FLOOR O UTLETS HEATER HEATER
M A X A/C ON HI
INSI DE% DASH OUTLETS A/C HEATER
NORM A/C ON
A L L OUTSIDE
DASH O UTLETS
A/C
HEATER
B I-LE V E L
ON A L L OUTSIDE
FLOOR AND
DASH O UTLETS
A /C &
HEATER
HEATER
VE N T OFF A L L OUTSIDE DASH O UTLETS
A/C HEATER
HTR
OFF A L L OUTSIDE
FLOOR OUTLETS
HEATER HEATER
DEF ON A L L OUTSIDE DEFROST O UTLETS HEATER DEFROST
NOTE % 100% Inside air is n ot availab e, some bleed through o f outside air is allowed.
Fig. 1 B 1 1 -S y s te m O peration - CK Truck
Fig. 1B- 12 -Air C o n d itio n ing Vacuum Schem atic - CK Truck
O VER H EA D SYSTEM (C-K M ODELS)
T his system operates in conjunction with the Four-
Season System. Since re frig e ran t flow is controlled by the
fro n t system, the only control provided for on the
o verhead system is a three-speed fan switch (LOW ,
M ED , HI). T h e fan switch is m ounted in the instrum ent
panel, to the right o f the steering coloumn (fig. IB-13.
In the O F F position, the blower is inoperative;
however, re frig eran t is circulating in the system if the
Four-Season System is ON. In any o f the three blower
positions (LOW , M ED , HI), the blower will be operative
regardless if the Four-Season System is ON.
N O TE: To o b ta in m axim um cooling, the Four-
Season System should be on A /C , tem perature