1967 CHEVROLET CAMARO Wiring

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-66

Fig.
93—Chevelle Four-Season Ducts

8. Remove the radio speaker and grille.

9. Remove the right outlet duct.

10.
Disconnect the bowden cables from their brackets

and operating levers on the distributor assembly.

11.
Disconnect the flexible tubing from the center and

left side outlet ducts at the air distributor assembly.

12.
Remove the heated air distributor ducts from the

air-distributor assembly.

13.
Remove the single remaining distributor to dash

panel attaching nut (the others were removed from

beneath the hood when the core cover was removed

in Step 2) located at the right end of the air dis-

tributor assembly.

14.
Carefully pull the assembly out from under the

dash, disconnecting the compressor switch wiring

connector and the water valve control switch vacuum

lines.
Installation

Reverse the removal procedure to reinstall the air

distributor assembly.

COMFORTRON AUTOMATIC

CONTROL COMPONENTS

The Comfortron system is the same as the Chevrolet

Four Season system insofar as the basic system compo-

nents are concerned. , Most removal and installation

procedures wUl remain as stated for the Four Season

system except where the automatic control components

are encountered. Each such component will be covered

in the pages which follow.

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-71

SUN-AMBIENT

SENSOR AND COMPRESSOR

CLUTCH SWITCH

HIGH BLOWER

DELAY RELAY

THERMAL

VACUUM

VALVE

Fig.
102-Comfortron Underhood Wiring

use when inspecting a damaged vehicle equipped with air

conditioning.

1.
Remove the drive belt. Cut belt off if necessary.

2.
Visually inspect the condenser, receiver-dehydrator,

compressor, mounting brackets, conditioning unit, all

connecting lines, and all controls to determine the

extent and nature of the damage.

a. No repairs, such as soldering, welding or braz-

ing, should be attempted on the condenser be-

cause of its construction. If the vapor passages

in the horizontal tubes or return bends or mani-

folds have been damaged in any way, the con-

denser should be replaced with a new one.

b.
The receiver-dehydrator should be replaced if

there is any evidence of its having sustained

either internal damage or a fracture at any of

the lines or welded joints or if the system has

been exposed to the atmosphere for an undeter-

mined period of time.

c. Examine the compressor for any visible external

damage.

d. The evaporator should be examined for damage

and, if necessary, removed or replaced or the

entire unit processed where damaged or exposed

to the atmosphere.

e. All connecting lines and flexible hoses should be

examined throughout their entire length for dam-

age.
If damaged in any manner, replace with new

lines.
f. Check all controls and connecting wires for

damage and replace with new parts where needed.

g. Check the clutch pulley for proper operation and

freedom from damage.

3.
Install gauge set.

4.
Purge the system. Pressure should not exceed 3 to

5 pounds.

5. Remove the compressor from mounting and remove

the oil test fitting.

6. Pour out the oil into a clean glass container and ex-

amine it for any foreign substance such as dirt,

water, metal particles, etc. If any of these are

present, the compressor and receiver-dehydrator

should be replaced and the other system components

should be flushed with liquid refrigerant.

7. If the oil is clean and free of any harmful substance,

replace oil with Frigidaire Oil available through

Parts Stock.

NOTE:
If the system components have been

replaced or flushed, replace the full charge of

oil. If not, add no more fresh oil than was

drained in Step 6.

8. Charge up the compressor to drum or can pressure

and leak test the compressor seals prior to in-

stallation of compressor.

9. Reinstall the compressor and evacuate the system

by following the Evacuating Procedure.

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-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 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