1967 CHEVROLET CAMARO battery

HEATER AND AIR CONDITIONING 1A-62

2.
Insert the evaporator assembly into the outlet case

half and mount the evaporator, thermostatic switch,

and cable to the case.

3.
Install the face plate to the case and install control

retaining nuts and knobs.

4.
Assemble the case halves and mount the evaporator

pipe clamp.

5. Install the evaporator assembly as previously

described under EVAPORATOR.

BLOWER ASSEMBLY

Four-Season System

Chevrolet and Camaro

Removal

1.
Disconnect battery ground cable.

2.
Remove the right front fender and skirt assembly.

3.
Disconnect the motor wire at the flange connector.

4.
Disconnect the rubber air cooling tube from the

motor.

5. Remove the motor to case attaching screws and re-

move the blower assembly. If the sealer acts as an

adhesive, pry the assembly carefully away from the

6. Remove the blower from the motor shaft.

Fig.
86—Blower Assembly—Four-Season (Chevrolet,

Chevelle, Camaro)
Installation

1.
Mount the blower to the motor shaft with the open end

of the blower away from the motor.

2.
Mount the assembly to the case with the attaching

screws.

3.
Connect the rubber tube and blower wire to the

motor.

4.
Replace the right front fender and skirt assembly.

5. Connect battery ground cable.

Chevelle

The blower assembly (fig. 86) is mounted to the dash

panel and contains the outside air-recirculated air

diverter door, the heating-cooling diverter door, the air

conditioning relay and resistor, the compressor actuating

switch, and the blower motor.

Replacement

1.
Disconnect the blower motor "hot" wire at the con-

nector and the ground lead on the Chevrolet.

2.
Detach the rubber cooling tube from the blower as-

sembly and remove the five bolts attaching the

blower motor to the blower assembly.

3.
Remove the motor and fan, disassemble fan from

motor and install on a new motor. If, because of

engine accessories, hoses restrict lifting the blower

assembly from the engine compartment, remove

blower from motor and lift units out separately.

Assemble replacement units under the restricting

hoses.

4.
Reinstall motor and fan into blower assembly. Re-

place cooling tube, ground wire and connect hot wire

to connector.

5. Check blower operations.

Corvette

Replacement

1.
Remove the radiator overflow tank and brackets and

pull the tank out of the way as far as the length of the

heater hose will permit.

2.
Disconnect the electrical connector and the rubber

air inlet tube from the blower motor.

3.
Remove the five blower flange to case attaching

screws and carefully remove the blower motor and

drum assembly.

4.
Remove the blower drum assembly and reinstall on

a new blower motor.

5. Replace the blower motor and drum assembly in the

case and reinstall all screws, hoses and electrical

connections.

All-Weather System

Chevy II

Removal

Under the Hood

1.
Purge the refrigerant from the system.

2.
Drain the radiator.

3.
Remove the refrigerant hoses at the evaporator

pipes.

4.
Remove the evaporator pipe clamp and grommet.

5. Remove three nuts from the blower case studs which

pass through the firewall.

6. Remove heater hoses from core tubes.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-67

Fig.
94—Camaro Four-Season Ducts

Heater and Air Distributor Assembly

Removal

rfooo

1.
Disconnect battery ground cable.

2.
Drain radiator (do not purge refrigerant system).

3.
Disconnect all connectors attached to the Comfortron

wiring harness which are on the engine side of the

firewall. Push the wiring harness grommet through

the firewall to the rear.

4.
Disconnect the four vacuum hoses coming from the

underdash through the large firewall grommet. Push

the hose grommet through the firewall to the rear.

5.
Remove the nuts from the heater and air distributor

case studs which project through the firewall from

the dash side.

6. Disconnect the heater hoses from the core tubes.

Under Dash

1.
Remove glove box assembly.

2.
Remove the dash center face plate, ash tray assem-

bly, and any radio and/or tape equipment.

3.
Remove the Comfortron control assembly mounting

screws and lower the control unit.
4.
Remove the vacuum line from the kick pad valve

diaphragm.

5.
Disconnect all harness connectors between the Com-

fortron harness and the rest of the dash wiring.

6. Remove the air distributor duct which supplies the

dash outlets.

7.
Remove the screws attaching the heater and air

distributor to the firewall.

8. Pull the assembly rearward then down to remove

from the dash. Pull the Comfortron wiring harness

and vacuum hose assembly through the firewall.

Installation

1.
Place the entire case assembly with wiring, vacuum

hoses,
and control assembly into the car on the floor.

2.
Pass the underhood wiring harness and vacuum hose

harness as far as possible through the appropriate

firewall holes.

3.
Lift the assembly up into position and pass the case

studs through the firewall mounting holes. Attach

the case to the firewall with the mounting screws.

4.
Mount the dash outlet air distributor duct to the face

of the case.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-68

Fig.
95—Corvette Four-Season Ducts

5. Connect the various Comfortron harness connectors

to the dash wiring and connect the vacuum hose to

the kick pad valve diaphragm. Push the vacuum hose

harness and wiring harness through the firewall to

the proper location and install their respective

grommets.

6. Raise the control unit into place and install the

mounting screws. Check that all connections are

complete.

7. Replace any radio and/or tape equipment, the ash

tray assembly, and face plate.

8. Replace the glove box assembly.

9. Connect the heater hoses to the core tubes, and

attach the nuts to the case studs through the firewall.

10.
Reconnect the four vacuum hoses as follows: Purple

to the cylinder on the thermo-vacuum valve, yellow

tracer to the body of the thermo-vacuum valve, red

tracer to the vacuum source "Tee" connection, and

white tracer to the vacuum tank inlet.

11.
Connect the wiring harness to the underhood air

conditioning components.

12.
Refill cooling system, connect battery ground cable

and check system performance.

Vacuum Tank

The vacuum tank is mounted on the firewall as shown

in Figure 97. Notice that the two vacuum lines are

clamped to the vacuum tank ports. *

Thermal Vacuum Valve

This heat operated vacuum valve is located in the

heater core input line. Figure 98 illustrates valve instal-

lation with clamps attaching the water hoses as well as

the vacuum hoses in place.
Resistor Assembly

Figure 99 illustrates the location and installation of

the blower speed resistor assembly.

Relays

Two relays are used in the system, both mounted on the

evaporator case as shown in Figure 100. The mounting

bracket forms a common ground for the relays and as a

plug for the hole in the evaporator housing used in the

Four Season system for resistor installation.

Sensors (Thermistors)

Ambient Switch and Sensor

This combination unit, which engages the compressor

clutch at about 40°F and also senses outside air tem-

perature and sun load, is mounted to the firewall within

the engine compartment with its long neck extending

deep into the cowl vent plenum chamber. Figure 98 il-

lustrates this installation,

In-Car Sensor

This sensor is located beneath the lip of the instru-

ment panel overhand just to the right of the driver as

shown in Figure 101.

Removal

1.
Remove glove box assembly.

2.
Disconnect sensor wires connector at harness.

3.
Remove sensor mounting screws, remove sensor

and pull wires and connector through hole in dash.

Installation

1.
Insert connector and

through the dash hole.
wires of replacement sensor

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-73

Fig.
105—Comfortron Control Head

10.
Introduce R-12 vapor at cylinder (room) temperature

and pressure.

11.
Leak test all fittings and connections and give partic-

ular attention to a leak test at the compressor shaft

seal if compressor has not been leak tested on the

bench.

12.
Complete system processing and charge system.

FUSES

A fuse, located in the junction block protects the entire

air conditioning system except for the blower when op-

erating at high speed.

A second fuse, to protect the high speed blower circuit,

is located in the electrical wiring between the horn relay

and the Air Conditioner relay (except Universal). The
Universal unit has a fuse in the line between the ignition

switch and the Air Conditioner blower switch. See the

specification page for the proper replacement fuse.

FOUR SEASON HEATER COMPONENTS

Corvette

The heater components of the system are, in general,

much the same as those of the standard Corvette heater.

Heater hoses carry the engine coolant to the heater core,

located in the air distributor duct beneath the instrument

panel.

A significant difference is that in the Corvette Air

Conditioning System there is no flow through the heater

core until the COOL IN-HOT PULL knob is pulled out.

This movement opens the vacuum switch on the air

distributor assembly and allows vacuum to be applied

to the water valve mounted in the engine compartment,

opening the valve. Thus the heater core is unheated

until needed, at which time it receives full flow of the

engine coolant. Air passing through the core receives

maximum heat which is tempered by mixing with un-

heated air before entering the passenger compartment.

Heater Core

Replacement

The heater core in the Corvette Air Conditioning

System is removed in the same manner as the core in

the Corvette heater. The distributor assembly must first

be removed from under the dash as covered previously

in this section before the core can be removed and

replaced.

Water Valve

Installation of the water valve is illustrated in Figure

113.
An inoperative valve must be replaced.

Chevrolet

Heater Core

Removal

1.
Disconnect battery ground cable.

2.
Drain radiator

3.
Remove right front fender and skirt assembly.

Fig.
106—Comfortron Temperature Dial Adjustment
Fig.
107—Amplifier Removal

CHEVROLET CHASSIS SERVICE MANUAL

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

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

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

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