GENERAL INFORMATION 0-4
Fig.
1—Vehicle
Serial Number
Located on Left Front Hinge
Pillar—Chevrolet Shown
Fig.
2—Vehicle Serial Number and
Body Style, Body Number Trim and
Paint Combination Located on
Instrument Panel Brace
Under Glove Box—Corvette
Fig. 3—Four and Six Cylinder
Engine Unit Number Located on
Pad at Right Hand Side of Cylinder
Block at Rear of Distributor
Fig.
4—Eight Cylinder Engine Unit
Number Located on Pad at Front,
Right Hand Side of Cylinder Block
Fig.
5—Rear Axle Unit Number
Located Bottom Surface of Carrier
at Cover Mounting Flange—Corvette
Fig.
6—Rear Axle Unit Number
Located on Right or Left Axle
Tube Adjacent to Carrier
BSHfi^;^
PAINT
HRIKI5"tM>
fIHIsS
HE|St.>MfT*
^^ * *•'"
•<"'
Fig.
7—Body Style, Body Number
Trim Type and Paint Combination
Located on Upper Right Hand Side
of the Dash Panel—Chevrol et
Fig.
8—Body Style, Body Number
Trim Type and Paint Combination
Located on the Upper Left Hand
Side of the Dash Panel—Chevelle
and Camaro
Fig.
9—Body Style, Body Number
Trim Type and Paint Combination
Located on the Upper Right Hand
Part of the Dash Panel—Chevy II
1. Manufacturers identity number assigned to all
Chevrolet built vehicles.
2.
See Model Identification in this section.
3.
Last number of model year (1967).
4.
F-Flint
5.
Unit numbering will start at 100,001 at all plants.
KEYS AND LOCKS
Four keys (two hexagonal head and two round head) are
provided with each vehicle. The hexagonal-head key
operates the ignition switch and front door locks. The
round-head key operates the locks for the glove box and
rear compartment lid.
' Lock cylinders (except trunk) are furnished for service
uncoded, this necessitates the coding of these replace-
ment lock cylinders.
NOTE: In service, the trunk and glove box
lock cylinders are provided together with the
trunk lock cylinder coded and the glove box
cylinder uncoded.
The side bar type lock (fig. 18) is used for the ignition,
front doors and trunk. The glove box lock is of the wafer
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-2
DEFROSTER-q
DOOR
v-
HEATER
OUTLET
DEFROSTER
OUTSIDE
AIR
FROM PLENUM
OUTLETS
""•—
,
BLOWER
« 1
/ y
r J
\
AIR
DUQ
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DOOR
—-**
X J
HEAT
DOOR
HEATER
CORE
Fig. 2-Heater Schematic (Chevy 11)
CHEVY
II
Heater components are located under the instrument
panel in the passenger compartment. Hot water hoses
from the engine are routed to the fire wall to the heater
core pipes. The blower motor receives outside air from
the cowl vent plenum chamber through the adapter as-
sembly. The air enters the heater core chamber where
it either bypasses or passes through the core depending
on the position of the temperature door, controlled by
the TEMPERATURE lever on the instrument panel.
Temperature control is achieved by adjusting the position
of this door to vary the proportion of heated and unheated
air introduced to the car interior. As the air flow is
drawn out of the heater core chamber (in the desired
proportion of hot and cold), it enters the blower where
it is thoroughly mixed, assuring a uniform temperature.
The distributor guides the air flow through either the
floor outlet or the defroster outlets depending on the
setting of the DEFROSTER lever on the instrument
panel. The AIR-FAN lever is the air OFF control as
well as the blower control.
CONTROLS
Control Assembly (Chevrolet, Chevelle, Camaro,
and Chevy II)
Air-Fan Lever
Since the heater makes use of outside air only, this
lever serves as an "air on or off" control by actuating
a damper in the distributor assembly downstream ("up-
stream" in the Chevy n heater) from the blower assem-
bly. With the lever in the half-way position, this damper
will be open to allow airflow into the vehicle. Moving the
lever further will actuate the three-speed (LOW-MED-
HIGH) fan lever which controls the blower motor and
determines the volume and force of the air flowing
through the heater core into the car.
Temperature Lever
Through its bowden cable, this lever controls the
positioning of the temperature door in the distributor
duct. This door allows airflow through either the heater
core (full RIGHT) or the bypass duct around the heater
core (full LEFT). Because the water temperature is con-
stant, this knob acts as an air mixture control, control-
ling temperature by varying the proportions of heated
and unheated air blended in the heater distributor duct.
The cam lock device at the damper door operating
lever (Chevelle only) may be adjusted as follows: Loosen
the two attaching screws. Place the cam in the closed
position and insert a pin through holes provided, locking
the cam in this position. Rotate the entire assembly
toward the closed position. Hold closed with some force
and tighten attaching screws. Remove the locking pin.
Defrost Lever
The defrost lever controls the position of the damper
(or deflector) door located in the heater and defroster
assembly. In the "off" position full airflow will go to
the floor duct for car heating purposes. In the "de-ice"
position the diverter door will drop down and divert
almost all the airflow to the defroster duct. (This posi-
tion will seldom be needed except for extreme de-icing
requirements). A "detent" position is built into the
Fig. 3—Heater Control Panel (Chevrolet Shown as Typical)
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-3
linkage of this lever which will provide partial airflow
only to the defroster duct and which should be used for,
all normal defogging operations.
CORVETTE
Heater components are attached to the dash panel on
the right side of the vehicle with the air inlet assembly
on the engine side and the heater and air distributor
assemblies beneath the instrument panel within the pas-
senger compartment.
The heater operates on outside air only with the blower
receiving its air flow from the cowl vent plenum
chamber.
No water valve is utilized in the system. Therefore,
water flows through the heater core constantly while
the engine is running, keeping the core at maximum
temperature at all times.
Airflow through the system is shown in Figure 1.
Controls
Two knobs control all heater operations:
The FAN-TEMP knob is rotated to turn the blower
on and off and control blower speed and is pulled out
as desired to regulate heater temperature.
The AIR-DEF knob is the air on-and-off control as
well as the defroster control.
Temperature Damper: Door
At the heart of the heater operation is the temperature
damper door. Air from the blower follows parallel paths
through the distributor duct, with one path passing
through the heater core and the other path bypassing the
core.
The temperature damper door is placed in the duct
so that, when closed, the path of the heated air leaving
the heater core is blocked while the ambient air path
remains open. Positive closing of this door when no
heat is being called for is assured by a cam assembly
at the door operating lever. As the FAN-TEMP knob
is pulled out, the damper door is opened accordingly,
allowing varying proportions of heated air to mix with
the unheated airflow, thus providing heater outlet tem-
perature control. With the knob pulled fully out the
Fig.
4—Heater Controls (Corvette)
ambient air path is blocked and all airflow passes
through the heater core. Final heater output temperature
is dependent upon the proportion of heated and ambient
air blended together according* to the setting of the
temperature damper door.
Air and Defrost Damper Doors
Beyond the temperature damper door are the air door
and the defroster door, both operated through a single
bowden cable by the AIR-DEF knob. The first half of the
travel of this knob opens the AIR door allowing the
airflow to pass into the interior of the car through the
floor distributor openings. Pulling the AIR-DEF knob
fully out causes the defroster door to open, diverting
this airflow to the defroster ducts for defogging, de-
frosting or deicing operations.
NOTE: Since this knob is the air on-or-off
control, it should be pulled at least halfway out
before turning on the blower.
Fan Control
Rotate the FAN-TEMP knob to operate the three-
speed blower, increasing the velocity of the air through
the heater. The fully counter-clockwise position of the
knob is the off position. Turn clockwise to the desired
blower speed; fully clockwise for high blower speed.
COMPONENT REPLACEMENT AND REPAIR
CHEVROLET, CHEVELLE, AND CAMARO
Blower Assembly
Removal
1.
Disconnect battery ground cable.
2.
Unclip heater hoses from fender skirt.
3.
(Chevrolet and Camaro) Remove right front fender
and skirt assembly. (See Section 11 of the Service
Shop Manual)
(Chevelle) Move the vehicle front wheels to the
extreme right turn position. Remove all right front
fender retaining bolts. Allow the skirt to drop and
rest on top of the tire. To gain maximum clearance
for access to the blower motor attaching screws, a
block of wood may be wedged between the fender
lower flange and the top of the fender skirt. Position
the wood block so that the rear portion of the skirt
will be forced down and inboard. (See Figure 7.)
4.
Disconnect the blower motor wire at the motor
flange.
5.
Remove the motor to case mounting screws and re-
move motor. Pry the flange gently if the sealer acts
as an adhesive.
6. Remove the blower wheel retaining nut and separate
blower and motor.
Installation
1.
Assemble the blower wheel to the motor with the
open end of the blower away from the motor.
2.
Place the assembly into the case and replace the
mounting screws. Connect the blower motor wire to
the motor.
3.
(Chevrolet and Camaro) Replace the fender and
skirt assembly.
(Chevelle) Replace the fender skirt.
4.
Clip the heater hoses to the fender skirt and connect
the battery ground cable.
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-5
them in their proper location. (See Figure 8)
12.
Refill radiator.
Defroster Duct
Figure 9 illustrates the defroster duct installation
on Chevrolet, Chevelle and Camaro vehicles.
Bowden Cobles
Bowden cable attachment should be made in the fol-
lowing manner:
1.
With the cables attached to the control assembly
and levers, move the levers to their fully left or
closed position.
2.
Attach cable wires to the heater valve levers and
tighten cable attaching bracket screws.
3.
Check for proper cable operation and readjust as
necessary.
Control Panel
Control panel installation is shown in Figures 10, 11,
and 12.
Fan Switch
Replacement
1.
Remove control assembly-to-instrument panel re-
inforcement attaching screws and push the control
assembly toward the front of the vehicle and down.
2.
Remove the two switch attaching screws and the
electrical connector.
3.
Replace switch, screws, and electrical connector.
4.
Place control assembly into instrument panel and
replace attaching screws.
Resistor
The resistor assembly is attached to the heater dis-
tributor assembly. It should "be replaced if low or
medium blower speed is inoperative. Remove the glove
box for access to the unit.
HEATER HOUSING
LOWER RIGHT HAND
RETAINER NUT
Fig.
6—Air Distributor Duct (Camaro)
Fig.
7—Access to Blower and Housing (Chevelle)
CHEVY II
Heater Assembly
Removal (Fig. 13)
1.
Drain radiator.
2.
From within engine compartment;
a. Remove heater hoses from heater inlet and outlet
connections.
b.
Remove three nuts around blower motor attaching
heater assembly to dash panel.
3.
From within vehicle:
a. Remove glove box and glove box door.
b.
Remove screw attaching distributor bracket to
dash.
c. Remove the screw attaching case bracket to the
adapter assembly bracket.
d. Carefully detach heater assembly from dash panel
and adapter assembly and lower it toward floor of
vehicle.
e. Disconnect all bowden cable connections, the
wiring connector and the defroster hoses.
4.
Remove the heater assembly from the vehicle.
Core Replacement
1.
'With the heater assembly removed from the vehicle,
remove the screws attaching the core cover to the
heater assembly.
2.
Remove the core mounting screws and remove the
core from the assembly.
3.
Replace with a new core and replace the core cover.
Installation
1.
Be sure the adapter seal and blower motor seal are
in place and set into place beneath the instrument
panel.
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-9
Fig.
15-Heater Control Assembly and Cables (Chevy II)
Resistor Removal
Two screws attach the resistor to the rear side of
the heater assembly.
Heater Assembly
Removal
1.
Drain the radiator.
2.
Remove the radiator supply tank from its support
Fig.
16—Heater Hose Routing (Chevy II)
straps and move it out of the way.
3.
Remove the battery.
4.
Remove the water supply hoses from the core
connections.
5. Remove the blower and air inlet assembly as de-
scribed above.
6. Remove the glove compartment and the panel on
either side of the instrument panel console as out-
lined in the Body Section of this manual.
Fig.
17—Corvette Heater and Blower Inlet Assembly
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-10
PLATE RETAINERS
CORE BRACKET SCREWS
Fig.
18—Corvette Heater Core Removal
7. Place a protective covering (waterproof if possible)
over the carpeting under the heater.
8. Remove the two bowden cables from the instrument
panel and disconnect the wiring connectors from the
blower switch and from the resistor.
9. Carefully work the heater assembly out from beneath
the dash.
Core Removal
1.
Remove the heater assembly as described above.
2.
Remove the sheet metal nuts which retain the core
mounting plate to the core housing.
3.
Remove the screws attaching the core brackets to
the core mounting plate and separate the core and
plate. .
Installation
1.
Assemble the core to plate with non-hardening
sealer. Attach the core mounting screws.
2.
Attach the core and plate assembly to the case with
the two sheet metal nuts. The assembly is ready for
installation as described below.
Heater Assembly Installation
1.
Carefully position the heater assembly in place on
inner surface of dash panel, then install the blower
and air inlet assembly on heater studs extending
through to the engine side of the panel. Attach the
seven stud nuts.
2.
Install electrical connectors to the blower switch and
resistor and reinstall the bowden cables to the
instrument panel.
3.
Replace the blower electrical connectors.
4.
Replace the heater hoses. (See Figure 20)
5. Replace the battery and the radiator supply tank.
6. Refill the radiator and check for leakage.
7. Check heater operation and make control adjustments
as necessary.
8. Replace the console panels and the glove
compartment.
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-18
HIGH BLOWER
i DELAY RELAY
AMBIENT-SUN
SENSOR AND
COMPRESSOR SWITCH
Fig. 29—Comfortron Engine Compartment Components
COMFORTRON SYSTEM
The Chevrolet Comfortron Air Conditioning System is
basically the same as the Chevrolet Four-Season system
but with the additional feature of completely automatic
control. See Figures 28, 29 and 30 for views of the
Comfortron system. To the customer, the most notice-
able difference between the two systems, will be in the
control panel. In place of the three-lever/one-switch
panel of the Four-Season system, the Comfortron has a
single control lever plus a temperature dial similar to
that found in a home thermostat. After the dial is set to
the desired temperature indication and the lever is moved
to place the system in operation, the Comfortron will
automatically control the heating and air conditioning
functions to maintain the selected interior temperature
regardless of changes in outside air temperatures.
Most Comfortron parts are located in the passenger
compartment, (fig. 28)
Jn-Car Sensor
The function of the in-car sensor is to determine the
temperature of the interior of the automobile. It is
located beneath the overhang of the instrument panel.
Feedback Potentiometer
The feedback potentiometer indicates to the amplifier
system the position of the temperature door.
Control Head
A thumb wheel is provided to select the desired in-car
temperature. A control lever performs the following
functions:
1.
Operates a switch that allows the customer to select
the type of blower program desired.
2.
Operates the control head vacuum switch except
when the TEMPERATURE lever is in the OFF
position, thus programming the vacuum system.
3.
Operates the defroster through the control head
vacuum switch. The defroster door is partially
opened in the "DE FOG" position, and fully open in
the "DE ICE" position.
A two transistor amplifier is located on the bottom
side of the control head. It receives information from
the sensors, and in turn operates the transducer.
Fig. 30—Comfortron Control
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-21
"De-Fog"
Position
In the event that the front windshield should require
removal of a fogging condition, the owner at his option
may direct air to the windshield. The "De-Fog" position
directs part of the air to the windshield while retaining a
certain amount through the floor outlets. The temper-
ature of the air remains the same as it was prior to the
control being placed in the "De-Fog" position. Five
blower speeds are available. The temperature of the air
and the blower speed are selected by the automatic
controls and are dependent upon the in-car temperature.
"De-Ice" Position
The "De-Ice" position provides full heat with "Hi"
blower directing the entire airflow to the windshield to
melt ice. The automatic controls are completely defeated
and as a result, full heat with "Hi" blower are the only
conditions that can be received. The system will turn on
immediately in this position even though the engine
coolant might be cold.
General Information
Three start up conditions can be achieved with
Comfortron.
Weather
Cold
Method of Starting System
System starts as soon as engine coolant is
hot.
Hot System starts immediately when AC is
required.
Any System starts immediately in "De-Ice"
position.
UNIVERSAL SYSTEM
A self-contained unit, the dealer installed Universal
System operates on recirculated air only and entirely
independent of the vehicle heater. Recirculated inside air
is drawn into the unit, passed through the evaporator core
and into the car through the adjustable outlets in the
evaporator case. The entire unit mounts compactly
beneath the dash. Temperature control is by means of a
thermostatic switch.
The compressor used with the Universal System is
identical to that used for the Four-Season system except
for displacement. Underhood components are similar in
placement to the Four-Season system.
Controls
Universal system controls are the AIR knob controlling
the three speed blower motor switch and the TEMP knob
which controls the setting of the thermostatic switchi
Switch adjustment is covered elsewhere in this section.
When operating this system the Heater must be fully off.
CHEVY II ALL-WEATHER SYSTEM
The Chevy n All-Weather Air Conditioning System,
Figure 33, operates in conjunction with the heater to
provide a complete air conditioning system operating on
either outside air, recirculated air or a combination of
both. The cooling unit attaches to the heater distributor
and utilizes the heater blower. Several controls allow
full use of either the heating or cooling features of the
system. During marginal weather, it is possible to pro-
vide heated air at floor level and cooled air at breath
level.
A schematic view of the air conditioning underdash
components is provided in Figure 34 to aid in under-
standing airflow and control operation.
The evaporator assembly, located in the passenger
compartment attached directly to the heater distributor,
contains the evaporator core, expansion valve, thermo-
static switch and the air conditioning "ON" knob. The
thermostatic switch, utilized as the cooling control, feels
the temperature of the cooled air leaving the evaporator
core and turns the compressor on and off in accordance
with cooling needs. Refrigerant lines connect the evap-
orator assembly to the other system components located
in the engine compartment.
The six cylinder air conditioning compressor, com-
pletely field serviceable, is bracket-mounted to the
engine and is belt driven from the crankshaft pulley. A
muffler assembly, designed to eliminate compressor
pulsations is an integral part of the compressor con-
nector block. The condenser is mounted on the radiator
support just ahead of the engine radiator. The receiver-
dehydrator, with its sight glass, is located on the right
fender skirt.
Controls
Control of the air conditioning system is achieved
through the use of the heater control on the instrument
panel as well as the two knobs located on the air condi-
tioning unit itself (fig. 35).
Air Conditioning "ON" Knob
Labeled "Pull for Air Cond.", this knob diverts air-
flow from the floor distributor and through the air condi-
tioning unit. Initial movement of this knob also actuates a
switch, located at the damper door, which energizes the
compressor clutch thus putting the system into operation
and under the control of the thermostatic switch.
Temp-Cool Knob
This knob controls the thermostatic switch. Turn the
knob clockwise for more cooling, counter-clockwise for
less cooling.
Air Lever
This lever actuates the damper within the assembly
which chooses between recirculated air or outside air.
Fig.
31-Universal Air Conditioning Unit
CHEVROLET CHASSIS SERVICE MANUAL