Page 97 of 659

HEATER AND AIR CONDITIONING 1A-74
Fig.
108—Comfortron Power Servo Installation
4.
Disconnect heater' hoses from heater core (at
firewall).
5. Remove glove box door.
6. Remove glove box interior.
7. Disconnect right, left, and center air conditioning
outlet hoses from distributor duct.
8. Remove air distributor duct from heater
housing.
9. Disconnect hose and cable clamps from heater
housing.
10.
Remove the remaining three heater housing stud
retaining nuts (engine compartment) and one upper
retaining screw (inside vehicle).
11.
Pull the unit away from the firewall and out of the
car.
ADJUSTMENT
SCREW
Fig.
109—Mode Shift Vacuum Diaphragm
Fig. 110'—Compressor Mount—L-6 Engines (Typical)
12.
Remove heater.housing cover from heater housing.
13.
Remove heater core from heater housing cover by
removing four (4) retaining screws and two "U"
clamps.
14.
Remove heater core.
Installation
1.
Replace core in case using a non hardening sealer.
Attach the core clamps and retaining screws.
2.
Attach the heater housing cover to the housing.
3.
Position the unit against the firewall and attach
it with the retaining screw at the top of the case.
4.
Attach the sheet metal nuts to the case studs which
project through the firewall to the engine side.
5. Connect the control cables to the control doors and
case.
6. Attach the air distributor duct to the case.
7. Connect the left, right, and center outlet hoses.
8. Replace the glove box assembly.
9. Connect heater hoses to core tubes.
10.
Replace fender assembly.
11.
Fill cooling system and connect battery cable.
Camaro
Lower Heater Hose
Removal
1.
Drain radiator.
2.
Remove side mouldings and retainers.
3.
Remove lower fender attaching bolts.
4.
Remove skirt to fender and skirt to reinforcement
bolts.
5. pry the skirt away from the fender flange and away
from the firewall. Block the skirt (four inchlengtti
of 2 x 4) clear of the lower hose and proceed with
the hose replacement.
Installation
1.
Connect the hose.
2.
Remove the block, move the skirt into position and
install all attaching bolts.
3.
Replace fender attaching bolts and mouldings.
4.
Refill cooling system.
CHEVROLET CHASSIS SERVICE MANUAL
Page 98 of 659
HEATER AND AIR CONDITIONING 1A-75
283-327 V-8
CHEVROLET, CHEVELLE AND CAMARO
396-427 V-8
CHEVROLET AND CHEVELLE
283-327 V-8
CHEVY II
Fig.
Ill—Compressor Mount—V-8 Engines
COMFORTRON HEATER COMPONENTS
Heater Core
Removal
1.
Remove the core case as previously described under
Heater and Air Distributor Assembly.
2.
Remove the screws attaching the die cast plate to
the air inlet side of the case. Disconnect the tem-
perature door linkage at the door shaft.
3.
Remove the die cast plate with core from the case.
Remove the core mounting screws and remove core.
Installation
1.
Seal the core to the cast plate with non-hardening
sealer and attach the core with the mounting straps
and screws.
2.
Install the plate to the case and connect the tem-
perature door linkage.
CHEVROLET CHASSIS SERVICE MANUAL
Page 99 of 659

HEATER AND AIR CONDITIONING 1A-76
Fig.
112—-Heater Core Removal—Four-Season System (Corvette)
3.
Replace the core case into the car as described
under Heater and Air Distributor Assembly.
COMPRESSOR
The same basic six.cylinder reciprocating compressor
is used in all systems.
Two variations of the basic compressor are used. One,
with a displacement of 12.6 cu. in. is used with the Four-
Season System. The second model, having displacement
of 10.8 cu. in. is used with the Universal and All-Weather
Systems.
AH Systems
Removal
1.
Purge the refrigerant from the system.
2.
Remove connector attaching bolt and connector. Seal
connector outlets.
3.
Disconnect electrical lead to clutch actuating coil.
4.
Loosen brace and pivot bolts and detach belt.
5. Remove the nuts and bolts attaching the compressor
brackets to the mounting bracket.
6. Before beginning any compressor disassembly, drain
and measure oil in the compressor. Check for
evidence of contamination to ..determine if remainder
of system requires servicing. Compressor Servicing
information is located in the Chassis Overhaul
Manual.
Installation
1.
li oil previously drained from the compressor upon
removal shows no evidence of contamination, replace
a like amount of fresh refrigeration oil into the com-
pressor before reinstallatLon. If it was necessary to
service the entire system because of excessive con-
tamination in the oil removed, install a full charge of
"fresh refrigeration oil in the compressor. (See
Checking Compressor Oil Charge under Checking
Oil)
2.
Position compressor on the mounting bracket and
install all nuts, bolts and lock washers.
3.
Install the connector assembly to the compressor
rear head, using new "O" rings.
4.
Connect the electrical lead to the coil and install
and adjust compressor belt.
5. Evacuate and charge the system.
6. Leak test the system and check for proper operation.
Fig.
113—Heater Hoses^-Four-Season System (Corvette)
CHEVROLET CHASSIS SERVICE MANUAL
Page 100 of 659
HEATER AND AIR CONDITIONING 1A-77
Compressor Belt Tension Adjustment
Adjust the compressor belt to the specifications shown
in the Tune-Up chart in the Engine section of this manual.
COMPRESSOR FAILURE
If the compressor has failed mechanically to the ex-
tent that metal chips and shavings are found in it, the
system should be checked for foreign material and
cleaned as described under Foreign Material in the
System.
CHEVROLET CHASSIS SERVICE MANUAL
Page 101 of 659

HEATER AND AIR CONDITIONING 1A-78
WIRING DIAGRAMS
Blower
Motor
Resistor
•
Asm
EVAPORATOR—v
ASM.
\
-Diode
(Arc I
suppressor)
^\
16B
—>
-COMPRESSOR
Clutch Coil
•To battery positive
(+) terminal
No vacuum
in hose
#3
Blower
intake
air
Outside
air entry
Valve
by vacuum
in
hose
#3
Valve
normally
closed (spring
held)
Inside
car
air
(Recirc.)
AIR INLET
VALVE
POSITION:
Outside
air
intake
Recirc. air'intake
CONTROL ASM
TEMP CONTROL LEVER
(Operates temp valve
cable
&
equipment
in
chart shown below)
Compressor
Sw.
(Normally closed
Temp valve
begins
to
open
valveV
cable
arm
•Fan Speed Selector Switch
Switch
lever
position
Off
Low
Med
High
Contacts
made
B
to
None
BtoL
B to L
&
M
B to
L
& H
Fan
speed
Low
Low
Med
High
Resistance
in series with
Bio Motor
Hi
Rl
(RiR2)/(Rl+R2)
None
•Blower switch contacts must
be
dosed
before
fan
switch will
be
operable.
COLD
(O.
A.)
COLD a.A.)
Blower
H
y—low
switch
M/
-med
(Norm,
closed
contacts)
Fan speed switch
(See chart
at
left)
To vacuum,
tank
EXTENSION—vy
Horn relay "Bat" WIRE
ASM
X
harness
terminal
V
.**-__.. ;_
1 I panel
Legend:
___. —
Production wiring
Wire
is
part
of
equip.
•—————* Air
conditioning
wrg.
| i
T Agn. sw.
accsy
I term.
I
Temp
Control
Lever
Position
OFF
VENT.
COLD(I.A.)
COLEKO.AJ
HOT
Blower
(Master)
switch
contacts
Open
Closed
Closed
Closed
Closed
Vac switch
connects
vac source
to hose
#
#2
#2
&
#3
None
#3
#2
&
#3
Compressor
switch
contacts:
Open
Open
Closed
Closed
Open
Blower
intake
air
Outside
car air
intake used
Inside
car air
recirculated
Outside
car air
intake used
.Outside
car air
intake used
Fig. 114—Chevrolet—Four-Season Wiring Diagram
CHEVROLET CHASSIS SERVICE MANUAL
Page 102 of 659
HEATER
AND AIR CONDITIONING IA-79
BAT.
CABLE
ASM
A/C
wrg fwd of
dash
exc
bat.
cables,
ext
wire
&
compressor
grd
wire
is
part
of engine wiring harness.
"COMPRESSOR"
SW:
"OFF" POSN
"ON"
POSN
RELAY
ASM
/-DASH
/
PANEL
RESISTOR
ASM
LUTCH
COIL
:OMI
GRD
WIRE
ASM
MPRESSOR
BAT.
TERM
ON START
MTR SOL
EXTENSION WIRE ASM
._
J
J
^-CONTROL
SW
CONTACTS
B TO NONE
BTOL
BTOL&M
BTOL6H
•IGN SW ACCSY TERM.
A/C wrg
to
rear
of
dash
of
inst pnl harness.
Fig.
115—CheveIle—Four-Season Wiring Diagram
CHEVROLET
CHASSIS SERVICE MANUAL
Page 103 of 659

HEATER
AND AIR
CONDITIONING
1A-80
EVAPORATOR ASM.
Blower
Motor
INSIDE VALVE
(Normally closed
-spring held)
PLENUM VALVE
(Normally open
-spring held)
Actuator
(Vacuum
operated)
Inside car air (Recirc*
CONTROL ASM
TEMP CONTROL LEVER
•(Operates temp valve
cable
&
equipment in
hart shown below)
Temp valve
begins to
16DG
Fuse (In-line^
COMPRESSOR
Clutch Coil DASH-
PANEL
•Fan Speed Selector Switch
Switch
lever
position
Off
Low
"HeST
High
Contacts
B to
None
BtoL
B to L b U
BtoL&H
Fan
speed
Low
Low
Med
High
Resistance
in series with
Bio Motor
Rl
Rl
RlR2)/(Rl+R2)
None
•Blower switch contacts must be closed
before fan switch will be operable.
-To battery positive
(-0 terminal
•
Horn relay
terminal"
"Batf
To vacuum
tank
EXTENSION
WIRE
ASM
(Normally closed
contacts-*vac
operated)
7
*- Fan speed switch
(See chart at left)
•/-Wire is
\ part of
I inst panel
harness
Legend:
— Production wiring
————
Wire Is part of equip.
•mmmmmmmmmmmmmm*
AIT
Conditioning
WTg*
Temp
Control
Lever
Position
OFF
VENT
COLD
a.A.)
COLD
(O.A.)
HOT
Blower
(Master)
switch
contacts
Open
Closed
Closed
Closed
Closed
Vac switch
connects
vac source
to hose #
#2
&
#3
#2
#3
None
#2
Compressor
switch
contacts^
Open
Open
Closed
Closed
Open
Blower
intake air
Outside car air
intake used
Inside car air
recir culated
Outside car air
intake used
Outside car air
intake used
Fig.
116—Camaro—Four-Season Wiring Diagram
CHEVROLET CHASSIS SERVICE
Page 104 of 659
HEATER AND AIR CONDITIONING 1A-81
HORN RELAY
r
CONN.-
14 BROWN
(TO FUSE
PANEL)
BATTERY
1
—I ^ COMPR
ESSOR
DASH y
V-^ PANEL \
GROMMET—%
1 \
_ J~ ") "^
>14 BLACK/RED STRIPE-
FUSE .20 AMP.
•WIRE ASM. BLOWER-
MOTOR
14 BLACK 1
IGNITION SWITCH1
(ACCESSORY
TERMINAL)
CONTROL SWITCH
-RESISTOR
CONN.
•14 TAN
•16 BLACK
LIGHT BLUE STRIPE
•THERMOSTAT CONTROL
EVAPORATOR & BLOWER ASM.
Fig.
117—Universal System Wiring Diagram (Typical)
CHEVROLET CHASSI