fuse CHEVROLET CAMARO 1967 1.G Chassis Workshop Manual

HEATER AND AIR CONDITIONING 1A-16

EVAPORATOR

CORE

\

BLOWER AND AIR I

INLET ASSEMBLY •

AIR

DOOR

OUTSIDE AIR FROM COWL VENT

DEFROSTER

DUCT

DEFROSTER

DOOR

COOLED AIR

OUTLETS

Fig.
25—Airflow—Four-Season (Cheyelie)

will be hot at all times. When, during cooling operations,

the air is cooled by the evaporator to below comfort

level, it is then warmed by the heater to the desired

temperature; during "heating only" operations the evap-

orator will not be in operation and ambient air will be

warmed to the desired level in the same manner. The

side dash outlets may be rotated to provide either soft,

diffused airflow or spot cooling. Rotate half way to shut

off airflow. The barrel type outlet in the center of the

dash will direct air up or down or, if desired, shut it off.

Controls

Four-Season System (Chevrolet, Camaro)

Full control of the Four-Season System is obtained

through the use of a single control panel (fig. 26). The

control knobs make use of bowden cables to activate the
various doors and switches necessary for system opera-

tion.
Therefore, control adjustment is a matter of

properly setting these bowden cables. The following

paragraphs explain each control.

Temperature Lever

The TEMPERATURE lever controls temperature door

position, compressor operation, and air selector door

position. When the lever is in the OFF position, the sys-

tem is totally inoperative; airflow is shut off, the fan

switch will not operate the blower, and the compressor

is off. In the VENT position, the air selector door is in

the "outside air" position and the blower is powered at

low speed. At any lever position other than OFF, the

blower will be powered at low, however, blower speed

may be increased by moving the FAN switch. When the

Fig.
26—Chevrolet Four-Season Controls
Fig.
27—CheveNe Four-Season Controls

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR. CONDITIONING 1A-24

Fig. 35-Controls-AII Weather (Chevy II)

The heater components of the system are similar to

the standard Corvette heater with hoses routing engine

coolant to and from the heater core. A vacuum operated

shutoff valve assures that no coolant will pass through

the heater core until the system calls for heat.

Four control knobs surrounding the clock on the in-

strument panel center console provide full control of the

heating and cooling functions of the air conditioning

system.
The general arrangement of the system components

is pictured in Figure 37 while a schematic view of the

system will be found in Figure 36.

Controls Corvette

Four control knobs, grouped around the clock on the

instrument panel central console, provide full control

of the heating and cooling functions of the Corvette Air

Conditioning System. Each of the knobs, through a bowden

cable, operates one of the air diverter doors in the air

distributor assembly. In addition, the AIR COND.-PULL

knob operates the compressor switch; blower speeds are

controlled by turning the AIR PULL knob; and the heater

hot water valve vacuum switch is actuated by the COOL

IN-HQT PULL knob.

Air Conditioning "ON" Knob

The "AIR COND. PULL" knob controls the positioning

of the air diverter door which routes conditioned air

through either the dash diffuser ducts or the floor dis-

tributor outlets. Movement of this knob (hence, movement

of the selector door) also controls' the compressor

switch. When the door is positioned to send air through

the dash outlets the compressor is automatically turned

on to place the cooling system in operation and the fan

is turned on to LOW speed.

Blower Switch and Air Selector

The AIR PULL-FAN knob operates the selector door

in the right hand plenum chamber and may be set to allow

full outside air, full inside air, or a mixture of the two to

DEFROSTER DOOR

OPERATED BY

DEFROSTER KNOB
AIR CONDITIONING DOOR

OPERATED BY

AIR COND. PULL KNOB
BLOWER

OPERATED

BY TURNING

AIR KNOB

AIR DOOR

OPERATED

BY PULLING

AIR KNOB

OUTSIDE

AIR

CONTROLS

HEAT DOOR

OPERATED BY

COOL IN-HOT PULL

KNOB

L.H. OUTLET
CENTER

OUTLET
R.H. OUTLET
AIR COND.

PULL
COOL IN

HOT PULL

AIR PULL

LO-MED-HI
DEFROSTER

PULL

Fig.
36—Corvette Four-Season System Schematic

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-30

Leak Detector

Tool J-6084 (fig. 43) is a propane gas-burning torch

which is used to locate a leak in any part of the system.

Refrigerant gas drawn into the sampling tube attached to

the torch will cause the torch flame to change color in

proportion to the size of the leak. Propane gas fuel

cylinders used with the torch are readily available

commercially throughout the country.

CAUTION: Do not use lighted detector in any

place where combustible or explosive gases,

dusts or vapors may be present;

Operating Detector

1.
Open control valve only until a low hiss of gas is

heard, then light gas at opening in chimney.

2.
Adjust flame until desired volume is obtained. This

is most satisfactory when blue flame is approxi-

mately 3/8" above reactor plate. The reaction plate

will quickly heat to a cherry red.

3.
Explore for leaks by moving the end of the sampling

hose around possible leak points in the system. Do

not pinch or kink hose.

NOTE: Since R-12 is heavier than air, it is

good practice to place open end of sampling tube

immediately below point being tested, partic-

ularly in cases of small leaks.

CAUTION: Do not breathe the fumes that are

produced by the burning of R-12 gas in the de-

tector flame, since such fumes can be toxic in

large concentrations of R?»12.

4.
Watch for color changes. The color of the flame

which passes through the reaction plate will change

to yellow when sampling hose draws in very small

CHIMNEY

REACTION PLATE

BURNER HEAD

Fig.
43—Leak Detector
leaks of R-12. Large leaks will be indicated by a

change in color to a vivid purplish-blue. When the

sampling hose passes the leak, the flame will clear

to an almost colorless pale-blue again. If the flame

remains yellow when unit is removed from leak,

insufficient air is being drawn in or the reaction

plate is dirty.

NOTE: A refrigerant leak in the high pressure

side of the system may be more easily detected

when, if possible, the system is in operation. A

leak on the low pressure side may be most

easily detected after the engine has been shut

off for several minutes to allow system pres-

sures to equalize. This particularly applies to

the front seal.

VACUUM PUMP

A vacuum pump should be used for evacuating air and

moisture from the air conditioning system.

Vacuum pump, Tool J-5428, (fig.. 44) is available for

this purpose. It is used as a component part of the

Charging Station J-8393, described previously. The fol-

lowing precautions should be observed relative to tbe

operation and maintenance of this pump.

' • Make sure dust cap on discharge outlet of vacuum

pump is removed before operating.

• Keep all openings capped when not in use to avoid

moisture being drawn into the system.

• Oil should be changed after every 250 hours of nor-

mal operation.

To change oil, simply unscrew hex nut located on

back side of pump, tilt backward and drain out oil

(fig. 44). Recharge with 8 ounces of vacuum pump

oil.
If you desire to flush out the pump, use this

same type clean oil. Do not use solvent.

NOTE: Improper lubrication will shorten the

life of pump.

• If this pump is subjected to extreme or prolonged

cold, allow it to remain indoors until oil has reached

approximate room temperature. Failure to warm oil

will result in a blown fuse.

• A five ampere time delay cartridge fuse has been

installed in the common line to protect the windings

of the compressor. The fuse will blow if an ex-

cessive load is placed on the pump. In the event the

fuse is blown, replace with a five ampere time delay

fuse - do not use a substitute fuse as it will result in

damage to the starting windings.

• If the pump is being utilized to evacuate a burnt-out

system, a filter must be connected to the intake

fitting to prevent any sludge from contaminating the

working parts, which will result in malfunction of the

pump.

• Do not use the vacuum pump as an air compressor.

AVAILABILITY OF REFRIGERANT-12

Refrigerant-12 is available through Parts Stock in 25

lb.
drums and in 15 oz. disposable cans. Valves are

available for
the"
disposable cans, which may be used as

individual cans or as a group of up to four cans (fig. 45).

Tool J-6272 is used with one through four cans. The

use of the four-can fixture makes it possible to charge

the system with a known quantity of refrigerant without

CHEVROLET CHASSIS SERVICE MANUAL

HEATER
AND AIR
CONDITIONING
1A-31

FIVE
AMP

TIME DELAY

FUSE

CORD
TO

110
AC
SOURCE
PUMP

INLET
PUMP DISCHARGE

OUTLET

Fig.
44—Vacuum Pump

the use of weighing equipment necessary with the larger

drum. The single can Valve J-6271 can be used for com-

pleting the charge and for miscellaneous operations such
Fig.
45-R-12 Disposable Cans

as flushing. The valves are installed by piercing the top

seal of the cans.

Evacuating and charging procedures later in this sec-

tion will make use of the J-8393 Charging Station which

uses the 25 lb. drum of refrigerant.

COMPRESSOR OIL

Special refrigeration lubricant should be used in the

system. It is available in 1 quart graduated bottles

through Parts Stock. This oil is as free from moisture

and contaminants as it is possible to attain by commercial

processes. This condition should be preserved by im-

mediately capping the bottle when not in use.

See "Air Conditioning System Capacities" for the

total system oil capacity.

Due to the porosity of the refrigerant hoses and con-

nections, the system refrigerant level will show a definite

drop after a period of time. Since the compressor oil is

carried throughout the entire system mixed with the

refrigerant a low refrigerant level will cause a dangerous

lack of lubrication. Therefore the refrigerant charge in

the system has a definite tie-in with the amount of oil

found in the compressor and an insufficient charge may

eventually lead to an oil build-up in the evaporator.

COMPRESSOR SERIAL NUMBER

The compressor serial number is located on the serial

number plate on top of the compressor. The serial num-

ber consists of a series of numbers and letters. This

serial number should be referenced on all forms and

correspondence related to the servicing of this part.

INSPECTION AND PERIODIC SERVICE

PRE-DELIVERY INSPECTION

1.
Check that engine exhaust is suitably ventilated.

2.
Check the belt for proper tension.

3.
With controls positioned for operation of the system,

operate the unit for ten minutes at approximately

2000 rpm. Observe the clutch pulley bolt to see that

compressor is operating at the same speed as the
clutch pulley. Any speed variation indicates clutch

slippage.

Before turning off the engine, check the sight glass

to see that the.unit has a sufficient Refrigerant

charge. The glass should be clear, although during

milder weather it may show traces of bubbles. Foam

in.
the flow indicates a low charge. No liquid visible

indicates no charge.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-33

within the system. The following fixed conditions must be

adhered to in order to make it possible to compare the

performance of the system being tested with the stan-

dards below:

1.
Doors and windows closed. (Car inside or in shade.)

2.
Hood up and engine exhaust suitably ventilated.

3.
Vehicle in NEUTRAL with engine running at 2000

rpm.

4.
Air Conditioning controls set for -

• Maximum cooling.

• High blower speed.

5.
TEMP knob and AIR knob set for full recirculating

air. On Comfortron systems* move the control lever

to REAR and pull the white vacuum hose from the

transducer. Plug the hose. An alternate method is to

install the J-22368 Tester (described later in this

section) and operate it on MANUAL control to main-

tain maximum cooling and blower speed.

6. Gauge set installed.

7.
System settled out (run-in approximately
10
minutes).

8. A thermometer placed in front of vehicle grille and

another in the right hand diffuser outlet.

PERFORMANCE DATA

The following Performance Data define normal opera-

tion of the system under the above conditions. Relative

humidity does not appear in the tables because after

running the prescribed length of time on recirculated air

and maximum cooling, the relative humidity of the air

passing over the evaporator core will remain at ap-

proximately 35% to 40% regardless of the ambient

temperature or humidity.

Should excessive head pressures be encountered at

higher ambient temperatures, an 18" fan placed in front

of the vehicle and blowing into the condenser will provide

the extra circulation of air needed to bring the pressures

to within the limits specified.

NOTE: Higher temperatures and pressures will

occur at higher ambient temperatures, fti areas

of high humidity it is possible to have ther-

mometer and gauge readings approach but not

reach the figures listed in the performance

tables and still have a satisfactory operating

unit. However, it is important to remember that

low pressure has a direct relationship to nozzle

outlet temperature. If pressure is too low, ice

will gradually form on the evaporator fins, re-

stricting airflow into the passenger area and

resulting in insufficient or no cooling.

Four-Season and Comfortron System

Chevrolet and Camaro
Chevelle

(Refrigerant
Charge
=

Temperature
of Air

Entering Condenser

Engine rpm

Compressor

Head Pressure

Evaporator Pressure

at POA

Discharge Air Temp,

at Right Hand Outlet
3
Lbs. -

70°

145-

155

38-

41
80°

170-

180
12 02

90°
.)

100°

2000

205-

215

29.5 -

39-

42
41-

43
255-

265

30.5

42-

45
110°

260-

270

psi

43-

46
120°

295-

305

45-

48
(Refrigerant Charge =

Temperature of

Air Entering

Condenser

Engine rpm

Compressor Head

Pressure

Evaporator
Pressure

at
POA

Discharge Air

Temp, at Right

Hand Outlet
3 Lbs. -

70°

150

160

37-

40
80°

175

185
12 Oz.)

90° 100°

2000

210 250

220 260

29.5 - 30.5

37-

40
38-
39-

41 42
110°

280

290

psi

40-

44
120°

290

300

41-

45

Corvette

(Refrigerant Charge =

Temp, of Air

Entering Condenser

Engine rpm

Compressor

Head Pressure

Evaporator
Pressure

at
POA

Outlet
Air

Temperature

(at Right
Outlet)
3
Lbs.

70°

150-

170

38-

40
- 4 Oz.)

80°

175-

195

29

38-

40
90°

2000

200-

200
100°

i*pm

240-

260
110°

285-

300

5-
30.5 psi

40-

42
41-

43
43-

45
120°

325-

335

45-

47

Alt Weather System

Chevy II

(Refrigerant
Charge
=

Grille Air

Temperature

Engine rpm

Compressor Head

Pressure

Compressor Suction

Pressure**

Discharge Air Temp,

at R/H Outlet**
2-1/2 Lbs.)

70°

120-

140

13

32-

37
80°

150-

160

14
CO
OO
CO
CO
90°
100°

1500

175-

185

15

35-

40
220-

230

15

36-

41
110°

240-

250

19

37-

42
120°

265-

275

19

38-

43

**When Compressor Clutch Releases

COMFORTRON SYSTEM OPERATIONAL TEST

This test, designed as a quick check of total system

operation, must be made with the engine operating at

minimum of 2000 rpm and coolant warm. Wait several

seconds between operations to allow the system to move

through its sequence of operation and arrive at the pre-

scribed mode of operation.

1.
With control lever in the OFF position, and Tem-

perature Dial at 65°F.

a. System is turned OFF, there is no air flow from

any of outlets.

2.
Control lever in HI Front and Temperature Dial set

at65°F.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-34

a. Blower comes on High speed.

b.
Cold air comes from A/C outlets.

3.
Rotate Temperature Dial to 85°F.

a. Blower speed will decrease to Low speed then

increase to Medium or High.

b.
Air temperature changes from Cold to Hot and

comes out heater outlet.

4.
Move control lever to LOW Front, with Temperature

Dial at 85°F. Blower operates at Low and Medium

speeds.

5.
Move control lever to Rear, set Temperature Dial

at 65°F.

a. Blower goes to High speed and maintains high

air flow.

b.
All air comes from A/C outlets.

6. Move control lever to DE-FOG.

a. Blower is on Medium or High Speeds.

b.
Air comes from Defroster and Heater Outlets.

7.
Move control lever to DE-ICE.

a. Blower is on High Speed.

b.
Air temperature goes to warm and most of air

comes from defroster nozzle, with small amount

of air coming from heater outlet.

c. Outside air door is open - (door valve is closed

to car body).

8. Move control lever to REAR (dial at 65°). Outside

air door moves outboard. (Door valve is open to

car body).

CHEVROLET COMFORTRON TESTER

The J-22368 Automatic Temperature Control Tester

when in AUTOMATIC position, may be used to perform
Comfortron system checks without disturbing normal car

operation.

Under MANUAL control tester allows the operator to

set and hold a predetermined blower speed
and.
temper-

ature. The tester can also be used to measure external

system voltages by using the probe.

To Install the Tester

1.
Remove the three-terminal male connector from the

Amplifier on the Comfortron control head.

2.
Plug this connector into the three terminal female

connector (with yellow wire)
on
the Tester.

3.
Plug the remaining three-terminal male connector

on the Tester into the Amplifier on the control head.

4.
Attach the black ground lead to any good ground

point available in the car.

5.
Remove the large vacuum hose from Transducer and

connect it to the Tester vacuum hose nipple.

6. Connect the Tester vacuum hose (short hose) to the

Transducer.

Quick Test Procedure

With the J-22368 Tester installed as outlined above,

the following quick checks may be made to pinpoint

the cause of system malfunctions. This quick check

procedure is reproduced on the "swing out" plastic

instruction card attached to the back of the Tester.

Before performing the checking procedure, start the

engine and allow to run on fast idle until operating

temperature is reached. Then set the dash control lever

to HI-FRONT position and the dash control Temperature

Dial to 75° and proceed with the following steps:

Step

1

2

3

4

5A

5B
Tester Settings

Rocker

Switch

Manual

Manual.

Manual

Manual

Manual

Auto-

matic
Voltage

Source

Sensor

Amplifier

or

Control

Cal.

Trans-

ducer

Amplifier

or

Control

Cal.

Amplifier

or

Control

Cal.
Manual

Control

150

150

a. Max.

Heat*

b.
Max.

Cold*

a. Max.

Cold*

b.
Max.

Heat*

Set to

150 for

Comfortron

System

Same as 5A.

Allow 5 min.

for system

to stabilize

with doors

and windows

closed.
Tester Should

Indicate:

Battery Voltage

Battery Voltage

0-4 Volts

8 Volts Min.

8 Volts Min.

0-3 in. Vac.

0-4 Volts

9 in. Min. Vac.

6.5 Volts

5.5 to 7.5 Volts
To Correct Abnormal Indication:

Check fuse and wiring.

Check for open in sensor circuit.

See Service Manual:

Malfunctioning Amplifier or Temperature

Dial.

Check for open or bad ground in trans-

ducer circuit or replace transducer.

Rotate car temperature dial until meter

reads 6.5 volts. Car temperature should

'•- indicate 75°. If not, see temperature

calibration which follows.

After 5 minutes of operation check for

defective sensor.

•This setting should result in HIGH blower speed. Refer to shop manual for further operational checks.

CHEVROLET CHASSIS SERVICE MANUAL

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-40

THERAAAL VACUUM

VALVE
TO ENGINE

VACUUM

SOURCE

VACUUM STORAGE

TANK

OUTSIDE AIR

DIAPHRAGM

MODE

DIAPHRAGM

VACUUM

RELAY
BLACK

DEFOG-DEICE

DIAPHRAGM

GREEN

BLACKj ||
|
BROWN

CONTROL

VALVE

Fig.
50—Comfortron Vacuum Diagram

are fused which will lead to evaporator freeze-up.

Replace the switch.

• If the compressor does not operate regardless of

the position of the knob a loss of the power

element charge is indicated provided that it has

been established that power is supplied to the

switch. This, of course, results in no cooling.

Replace the switch.

• Check the screw threads for stripped or other-

wise damaged threads.

Adjusting Switch

H, after checks above, the switch seems to be operating

properly,

follows:
adjust for proper setting if necessary, as
1.
(Chevy II All-Weather) Turn the outer air deflector

in the face plate so that the attaching screws may

be removed; Then remove the control knobs, bezels

and the thermostatic switch. (Universal) remove the

face plate retaining screws. Pull the faceplate away

from the case when ready to turn the switch adjusting

screw.

2.
Vehicle must be set up as in Step 2 above.

3.
The suction side of the system, read on the low

pressure gauge, should pull down to the pressure

shown in the chart in Performance Test under the

ambient temperature at the time the switch is being

set.

4.
If the low side pulls down lower than the prescribed

pressure at the end of each cooling cycle, turn the

adjusting screw (See Figure 54) clockwise in single

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-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