1967 CHEVROLET CAMARO electrical

HEATER AND AIR CONDITIONING 1A-36

(These tests should be performed with the engine at operating temperature.)

SYSTEM CHECKS

Control

Head

Setting

High

Front

Lo

Front

Lo

Front

Hi

Front

Hi

Front
Tester Settings

Function

Manual

Manual

Manual

Manual

De-ice

65° on

Temp.

Dial

Hi

Front

Hi

Front

Hi

Front
Auto-

Matic

1 1

Auto-

matic

Manual

Manual
Manual

Control

Max.

Heat

Rotate

from

Max.

Heat to

Max.

Cold

150

Max.

Cold

Max.

Cold

Max.

Cold

Max.

Heat

Max.

Heat

Max.

Cold
Voltage

Trans-

ducer

Trans-

ducer

Ampli-

fier

Trans-

ducer

Probe

Probe

Trans-

ducer

Trans.
Tester Should

Indicate:

High Blower

Maximum Heat

Reduced Blower

Speed

Complete series of

blower changes from

Hi to Lo to Hi

again.

AMPLIFIE:

Remove conn, from c

Voltage reading she

Short this lead to grc

Voltage reading she

No voltage change in<

COMPRESSOR C

Cooling System

Operation

DE-ICE i

Assuming rest of

system is operating

normally: Max. Heat

1
to windshield.

SENSOR STR

•—

TRAtfSDtfC

0-3"
Vac. Reading

8 Volts Min.

9"
Min.
Vac.
Reading

0-4 Voltage Reading
If not, check

the following:

Fuse in Slock

In Line Fuse

High Blower

Delay Relay

Duct Delay

Thermistor

High Blower

Delay Sensor

Power Servo

Blower Switch

Resistor

Blower Motor

Wiring Harness

Blower Switch

Master Delay

Thermistor

Master Delay

Relay

Resistor

Power Servo

Blower Motor

CHECK

Resistor

I CHECK
Electrical Diagram

Probe Points:

1-2

8-9

10-21

20

18

19

*
9-46

-r

^2-3
15

16

Checked during

above procedure.

(This is a com-

plete step-by-step

high blower circuit

check which also

checks wiring

harness.)

4

5

6

L2-13

L4

""§2-15

39-46

1
16 1

14

22-40-42-44-15

.ontrol head temperature dial.

>uld be 9 volts minimum,

jund.

>uld be 0 volts,

iicates malfunctioning of amplifier.

JUTCJH CHUCK

Compressor Clutch

(Grille Temp, must

be above 40°.)

IRCUIT

Blower Switch

Master Delay

Relay

Transd

NGCl
ucer

Sensor String

2R CHECK

Transducer voltage

&t Max. Cold

position)

Transducer Ground

Hi Blower Outside

air (air door closed

to car body). Hot air

from heater outlets.

Hi Blower Recirc.

Air (air door open

to car body) cold air

from A/C outlets.
24-25-26-27-28
Voltmete

should re
ad

Battery Voltage

Battery Voltage

Battery Voltage

. Vtinimum
6
volts

Battery Voltage

Minimum
6
volts

Battery Vo]

Batterv Vo]
Ltage

Ltage

Battery Voltage

Batterv Voltage

3a

Bai
:terv Vo

tterv Vo
tage

tage

Minimum
6
volts

Batterv Voltage

Minimum
6
volts

Battery Voltage

Minimum
8
volts

Minimum 8 volts

Minimum 8 volts

Batterv Voltage

Minimum 8 volts

1 III • II »ll. —..• —•— . !!•• 1

Battery Voltage

3-23

20-10-21

38

29-30-31-32-33-

34-35-36

37-38

Defective Power Servo; Leak in Vacuum

System; Temp.; Door Link Disconnected

or Jammed; Defective Vacuum Relay

Valve

Defective Mode Door Diaphragm
Batterv Voltage

Battery Voltage

Zero Voltage

Battery Voltage

Battery Voltage

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-49

CHEVROLET

CHEVELLE

CHEVY II

CAMARO
the last possible moment. Be certain that the

direction of flow is correct before connecting

the pipes.

Chevrolet, Chevelle, Chevy II, and Camaro

Replacement

1.
Remove the receiver inlet and outlet connections and

the two receiver to fender skirt attaching screws.

2.
Carefully remove the receiver-dehydrator from the

vehicle.

3.
Replace the new receiver~dehydrator assembly in

the vehicle and install all attaching screws and re-

frigerant lines.

4.
Add one fluid oz. refrigerant oil, evacuate and charge

the system.

Corvette

Replacement

1.
Purge the system of refrigerant.

2.
Disconnect the "O" ring inlet

hose clamp outlet connection

openings.

3.
Remove the receiver-dehydrator to radiator support

bracket screws (production engine) or receiver-

dehydrator to condenser bracket screws (optional

engine) and remove the unit from the car.

4.
Install the new receiver-dehydrator applying 30 in.

lbs.
torque to the attaching screws.
connection and the

and tape the hose

NOTE:
Do not uncap the new receiver-

dehydrator until the last instant before

installation.

5.

2.

3.

Fig.
63—
Receiver-Dehydrator Mounting (Chevrolet,

Chevelle/ Chevy II, Camaro)
Connect the high pressure lines at the inlet (use a

new "O" ring and torque connection to 13 ft. lbs.)

and outlet (torque screw to 25 in. lbs.).

6. Add one fluid oz. refrigerant oil, evacuate, charge

and check the system.

Sight Glass Replacement-All Vehicles

If damage to the sight glass should occur, a new sight

glass kit should be installed. The kit contains the sight

glass,
seal and retainer. (See Figure 65.)

1.
Purge system.

Remove the sight glass retainer nut using a screw

driver and remove old glass and seal.

Install the new glass and seal and retainer nut, being

careful not to turn the nut past the face of the hous-

ing. To do so may damage the "O" ring seal.

4.
Evacuate and recharge the system.

EVAPORATOR

Chevrolet and Camaro Four-Season System

The evaporator and blower case assembly is designed

so that the core may be removed without the need for

removing the entire unit from the vehicle. Instead,

only the side cover must be removed.

Removal and Installation of Entire Assembly

1.
Remove the inlet line at the expansion valve and the

suction throttling valve outlet connection.

2.
Remove the electrical connector from the blower

motor.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-57

EVAPORATOR PIPES

DISTRIBUTOR RELAY GRD.

ASSEMBLY & WASHER

EVAPORATOR ASM.
BLOWER

SHROUD

(RACKET

(PART OF

BLOWER)

Fig.
76—Evaporator Removal—All Weather

7. Disconnect the thermostatic expansion valve to evap-

orator inlet connector, remove the power element

bulb from the evaporator outlet line and carefully

move .the valve and its inlet hose away from the

evaporator case.

8. Remove the electrical connectors from the relay

and resistor terminals.

9. Remove the screws attaching the evaporator case

cover to the case. See Fig. 79. The core is bracket

mounted to the cover and the entire core and cover

assembly may now be removed from the vehicle.

10.
Remove the two cover to core bracket screws and

separate the core from the cover.

11.
Install the new core to the cover being sure that the

grommets are properly installed around the inlet

and outlet lines.

12.
Reinstall the core and cover assembly into the evap-

orator case and replace the attaching screws.
13.
Reinstall the STV and expansion valves, the equal-

izer line connection and the evaporator oil bleed line

from the STV.

NOTE:
Use all new «O" rings.

14.
Reinstall the radiator supply tank, water valve and

vacuum line, and replace the heater hoses onto the

core pipes being sure not to switch the hoses. Then

refill the radiator.

15.
Add three fluid oz. refrigerant oil after installing a

new core, evacuate and charge the system.

EXPANSION VALVE

The thermostatic expansion valve is factory adjusted

and pre-set and cannot be adjusted after installation. A

malfunctioning valve must be replaced. However, before

proceeding, check all other possible causes of the trouble.

Make certain that the power element bulb is properly

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-60

Fig.
81-P.O.A. Installation (Camaro)

NOTCH IN SUPPORT

TO ENGAGE SLOT !N VALVE

WHEN VALVE IS ROTATED

TO ANGLE AS SHOWN

Fig.
82-P.O.A. Installation (Chevelle)
Fig.
83—P.O.A. Installation (Corvette)

3.
Remove the electrical connector at the switch to be

replaced.

4.
Remove the switch knob. Remove the switch retain-

ing screws
and:
switch.

Installation

1.
Insert replacement switch into face plate and attach.

2.
Install the switch knob and connect the wiring

connector.

3.
If the thermostatic switch is being replaced, the

capillary tube should be formed to the same shape as

the unit removed.

4.
Attach the capillary to the core (fin sensing type)

and replace the face plate and attaching screws.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-61

INSERT CAPILLARY

BETWEEN FINS AT

ARROW

Fig.
84—Thermostatic Switch Capillary Installation

All-Weather System (Thermostatic Switch Only)

Chevy II

Replacement (See Fig. 85)

1.
Remove both control knobs and control stem bezels

from the evaporator assembly.

2.
Remove the face plate attaching screws located in

the outer ball outlets and lift off the face plate.

3.
Remove the two thermostatic switch attaching

screws.

4.
Disengage the plastic plug attaching the thermostatic

switch capillary tubing to the face of the evaporator

core (fig. 84).

5. Draw the switch out of the case through the face plate

opening, disconnecting the electrical connectors.

6. Reinstall the new switch by reversing the removal

procedure.
Fig.
85—Thermostatic Switch Removal

unit as outlined under
ALL-WEATHER-PULL CABLE

All-Weather System

Chevy II

Removal

1.
Remove the evaporator

EVAPORATOR.

2.
Remove the screws which attach the front and rear

case halves.

3.
Remove clamp from the evaporator pipes and sep-

arate case halves.

4.
Remove face plate retaining screws located in outer

ball outlets.

5. Remove control knobs and retaining nuts.

6. Remove face plate.

7. Remove cable to case retaining screw and thermo-

static switch mounting screw.

8. Remove evaporator to case mounting screws.

9. Withdraw evaporator with cable and thermostatic

switch assembly. Be careful to prevent kinks in the

thermostatic capillary.
10.
Pull the cable out toward the air outlet side of the

evaporator.

Installation

1.
Pass the replacement cable through the same channel

in the evaporator fins. If a new evaporator is being

installed, a channel will need to be opened between

the evaporator fins. This may be done by pushing a

pointed pencil between the fins beginning at the air

outlet side of the core, two inches to the right of the

left side of the fins and between the third and fourth

tubes down from the top. The cable channel should

exit at the air inlet side of the core between the first

and second tubes down from the top.

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-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