1967 CHEVROLET CAMARO engine

HEATER AND AIR CONDITIONING 1A-56

BLACK & RED

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SWITCH -"A

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Fig.
73—Underdash Wiring—Universal System (Typical)

evaporator outlet pipes. Locate the bracket about

1/2" from the dash panel.

12.
Replace the inlet and outlet hoses and hose clamp

connections.

13.
Evacuate and charge the system. Add three fluid oz.

refrigerent oil after installing a new core.

14.
Check system performance.

Corvette

Replacement (Fig. 78)

1.
Purge the system of refrigerant.

2.
Drain the engine radiator. Then remove the radiator

supply tank from its brackets, the heater water

valve and vacuum line from the firewall, and the

heater hoses from the core pipes. Carefully fold the

hoses,
valve and tank away from the evaporator

case.

3.
Remove the right hand hood lock support.
SCREW DRIVER

(NARROW BLADE) T£

GROOVE

A. Insert screw driver in

tang toward terminal

B. Pry tang back out to

when reinstalled into
RMINAL

\ CONNECTOR

TANG

groove & press

to release.

insure locking

connector.

Fig.
74—Terminal Removal—Universal System

4.
Disconnect the expansion valve equalizer line con-

nection and the evaporator oil bleed line from the

POA.

5.
Disconnect the evaporator outlet to POA inlet

connector.

6. Remove the POA bracket to evaporator case attach-

ing bolts. Then carefully move the valve and its

outlet hose away from the evaporator case.

Fig.
75-Cable Removal-All Weather

CHEVROLET CHASSIS SERVICE MANUAL

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-63

Under Dash

7. Remove ash tray and retainer, and glove box.

8. Remove blower case to air inlet adapter bracket

retaining screw.

9. Remove screw attaching air distributor to firewall.

10.
Remove nuts retaining evaporator case to lower lip

of dash. Withdraw evaporator drain tubes.

11.
Lower complete heater - air conditioning assembly.

12.
Remove screw retaining blower case to air distrib-

utor and separate them.

13.
Remove blower to case attaching screws. Disconnect

motor wire and remove blower assembly.

14.
Remove blower from motor shaft.

Installation

1.
Assemble blower to motor shaft.

2.
Mount motor in blower case and connect wire.

3.
Assemble blower case to air distributor and install

retaining screw.

4.
Lift the complete assembly into place and install

attaching screws and nuts.

5. Replace ash tray retainer and tray and glove box.

6. Replace nuts (engine side of dash) on heater case

studs and connect heater hoses.

7. Replace evaporator pipe clamp and grommet.

8. Replace the refrigerant hoses.

9. Evacuate and charge the refrigeration system and

refill the cooling system.

10.
Check system performance.

Universal Blower Assembly

Removal

1.
Remove the universal unit from its dash mounts.

2.
Remove the cover plate and separate the upper and

lower case halves. Remove blower motor mounting

strap screw and swing strap outward.

3.
Remove blower assembly. Loosen the blower wheel

setscrews and remove the wheels from the motor

shaft. . ' .
Fig.
88-Air Inlet Assembly (Chevrolet)

Installation

1.
Install the blower wheels on the motor so that the

lower blades curve toward the firewall side of the

unit when the motor is placed in the case. Tighten

the setscrews.

2.
Place the motor in the bracket with the electrical

connector side of the motor to the right side of the

bracket. Attach the mounting strap.

3.
Assemble the case halves and attach the cover plate.

4.
Remount the unit to the dash.

Fig.
87—Blower Assembly—Universal System
Fig.
89—Air Doors (Camaro)

CHEVROLET CHASSIS SERVICE

HEATER AND AIR CONDITIONING 1A-64

Fig.
90—Evaporator Wiring (Corvette)

AIR INLET VALVE

Four-Season System

Chevrolet

Figure 88 illustrates the vacuum valve which controls

the air inlet operation of the Four-Season System.

A vacuum tank and check valve is used to assure that

the air door will not change its position due to variations

in engine vacuum.

Camqro

Figure 89 illustrates the outside air inlet door assem-

bly, and the door in the kick pad which admits reeir-

culated air to the system.
BLOWER AND EVAPORATOR ASSEMBLY

(Corvette)

Replacement

1.
Remove the evaporator core as outlined under

"Evaporator Core Replacement".

2.
Remove the blower motor as outlined under "Blower

Motor Replacement".

3.
Remove the heater and air conditioning distributor

as outlined under "Air Distributor Duct Removal".

4.
Remove the remaining nuts attaching the blower

and evaporator assembly and the cover assembly

to the studs on the -firewall.

5. Replace the components removed by reversing the

removal, procedure.

AIR DISTRIBUTOR ASSEMBLY

AND OUTLET DUCTS

Four Season System

Chevrolet and Chevelle

Figures 92 through .95 illustrate the air distributor and

outlet ducts as used in the Chevrolet, Chevelle, Camaro,

and Corvette.

Corvette

Right Outlet Duct

Removal

1.
Remove the clamp screw at the inner end of the

outlet duct and loosen the clamp.

2.
Remove the screw and lock washer attaching the

duct outer mounting tab to the body hinge pillar

brace.

3.
Pull the duct and clamp down and away from the

distributor assembly. Disconnect the courtesy light.

4.
The duct extension assembly may now be removed

if desired as well as the deflector assembly. See

Figure 95.

AIR COND.

PULL
AIR PULL- DEFROSTER

FAN PULL HOT PULL

Fig.
91—Corvette Four-Season Controls

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-69

Fig.
96—Refrigerant and Vacuum Hoses (Corvette)

2.
Mount the sensor to the dash and connect the wires

to the Comfortron harness.

3.
Replace glove box assembly.

Control Head

The control head is attached to the instrument panel

flange in the same manner as the Four Season Control

Panel (See Figure 105). Two screws hold the head in

place. The amplifier, blower switch and servo and

defrost control cables are all part of the control head.

Amplifier

After the control head is removed from the instrument

panel, the amplifier may be removed as shown in Figure

107.

Temperature Dial Adjustment

1.
Install Tester J-22368 as previously described.

2.
Set Tester Voltage switch to Control Calibrate

position.

3.
Start the engine (fast idle) and set Comfortron

Control lever to HI-FRONT.

4.
Switch Rocker switch to MANUAL.

5. Set Manual Control Knob to 150 ohms on scale.

6. Rotate the Control Head Temperature Dial until the

voltmeter on the tester reads 6.5 volts. The Tem-

perature Dial should now indicate 75°.

7. If the Temperature Dial does not indicate 75°, insert

Tool J-21530 in slot to the left of the Dial as shown

in Figure 106.

8. With tool in position, rotate the Temperature Dial

so that it indicates 75°F.

Transducer

Figure 104 illustrates the installation of the transducer

assembly. Vacuum lines are clamped to the transducer

vacuum ports.
Fig.
97—Comfortron Vacuum Tank

CHEVROLET CHASSIS SERVICE JWANUAl

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