1967 CHEVROLET CAMARO diagram

HEATER AND AIR CONDITIONING 1A-35

Checking Condition of Thermistors (Sensors)

1.
Install Tester J-22368 as previously described.

2.
Start the engine and run at fast idle. Move the

Comfortron control lever to HI-FRONT.

•Set Rocker switch to MANUAL.

•Set Manual Control Knob to 150 ohms on scale.

3.
Set the Tester Voltage switch to AMPLIFIER.

4.
Rotate Comfortron Temperature dial until the Tester

voltmeter reads 6.5 volts. The dial should read 75°,

Adjust dial if necessary.

5.
After car has run (windows and doors closed) for at

least 10 minutes, switch Rocker switch to AUTO-

MATIC. Voltage reading should remain at 6.5. A

change in the voltage indicates a bad sensor.

6. If a bad sensor is indicated in Step 5, check each

sensor, disconnected from the system, with an ohm-

meter. Approximate resistance of each sensor at

75°F.
should be as follows:

In-car Sensor — 50-75 ohms

Ambient Sensor --,55 ohms or less

Duct Delay Sensor -.- 25-75 ohms

Feedback

Potentiometer —

Master Delay

Thermistor -- 70 ohms

High Blower Delay

Thermistor -- 80 ohms including

10 ohm resistor

(Located in Power Servo casting)
VACUUM
ELECTRICAL LEAD

GROUND

LEAD

Fig.
47—Comfortron System Tester x

COMPLETE SYSTEM CHECKS

The following information should be used whenever

preliminary checks indicate the need for further, more

specific, tests. Together with the Electrical Test Dia-

gram (fig. 49) and the Vacuum Diagram (fig. 50),

they may be used to accurately pinpoint any malfunction

of the system.

Fig.
48—Comfortron Tester Installation

CHEVROLET OU
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-38

HIGH BLOWER

DELAY RELAY

O) MASTER AND

HIGH BLOWER

DELAY RELAY

GROUND

Fig.
49A-Comfortron Wiring Diagram-Underhood

CHEVROLET CHASSIS SERVICE AAANUAL

HEATER AND AIR CONDITIONING 1A-39

BROWN

BROWN

LT.
GREEN

BROWN

DK. GREEN

CONTROL

SWITCH

N-CAR
SENSOR

"—ORANGE—(36

[y—LT. GREEN

*)WWWW 55|—jg

TRANSDUCER

POWER SERVO

HIGH BLOWER MASTER FEEDBACK

DELAY DELAY POTENTIOMETER

THERMISTER THERMISTER

Fig.
49B-Comforrron Wiring Diagram-Underdash

CHEVROLET CHASSIS SERVICE AAANUAL

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-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

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