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
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
HEATER AND AIR CONDITIONING 1A-81
HORN RELAY
r
CONN.-
14 BROWN
(TO FUSE
PANEL)
BATTERY
1
—I ^ COMPR
ESSOR
DASH y
V-^ PANEL \
GROMMET—%
1 \
_ J~ ") "^
>14 BLACK/RED STRIPE-
FUSE .20 AMP.
•WIRE ASM. BLOWER-
MOTOR
14 BLACK 1
IGNITION SWITCH1
(ACCESSORY
TERMINAL)
CONTROL SWITCH
-RESISTOR
CONN.
•14 TAN
•16 BLACK
LIGHT BLUE STRIPE
•THERMOSTAT CONTROL
EVAPORATOR & BLOWER ASM.
Fig.
117—Universal System Wiring Diagram (Typical)
CHEVROLET CHASSI
HEATER AND AIR CONDITIONING 1A-82
•BATTERY
(POS)
CABLE
NOTE
When
control
switch*
is !TOFF"
&
Air
Cond
is
"ON"
(Control
knob
pulled
but) the
blower
fan'will
run at low
speed.
CONTROL
SWITCH
CONNECTIONS
OFF
LOW
MED
HIGH
B
TO
NONE
B
TO L
BTOL&M
B
TO L
&
H
COMPRESSOR
GROUND
WIRE
ASM
BATTERY
(NEGATIVE)
CABLE
COMPRESSOR
ASM
DASHPAJSTEL
GROMMET
16DG
CONTROL
SWITCH
RESISTOR
ASM
14LBL
14BRN
CLUTCH
COIL
EXTENSION
WIRE
ASM
-14BRN--N
JUNC
BLOCKi
OSTATIC
SWITCH
CONTACTS
NORMALLY
CLOSED
STARTING
MOTOR
SOLENOID
BLOWER
MOTOR
AIR
COND
CONTROL
(PUSH-PULL)
KNOB
DOOR
SWITCH
(PUSH
BUTTON
NORMALLY
CLOSED)
RELAY
ASM
HORN
RELAY
DIVERTER
DOOR CABLE
FUSE
PANEL
EVAPORATOR
ASM
IGNITION SWITCH-
ACCESSORY TERMINAL)
Fig. 118—All Weather Wiring Diagram (Chevy II)
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-83
DIVERTER DOOR
CRANK POSITIONS:
AIR COND "ON"
AIR COND "OFF*
AIR COND SWITCH
(PUSH BUTTON,
NORMALLY CLOSED
CONTACTS)
BLOWER MOTOR
CONTACTS
NORMALLY
4D
16
16B/Y
COMPRESSOR
GROUND WIRE
ASM
BAT.
TERMINAL
ON STARTING
MOTOR SOLENOID
' BATTERY
CABLE ASM:
NEGATIVE
POSITIVE—*
- CONTROL SWITCH
SET AT:
•OFF
LOW
MED
HIGH
CONTACTS:
BTOBL
BTOL
BTOM
BT0M6B,
CLUTCH
HOUSING
liOli: WHEN CONTROL
SWITCH IS AT "OFF" &
AIR COND. IS "ON", FAN
WILL RUN AT LOW SPEED.
"AIR COND-PULL"
KNOB (SHOWN IN "ON"
POSITION)
TO REGULATOR
HORN
RELAY
16 BRN-BODY WIRING
HARNESS-837
14BRN
I
^
IA^RN
* IGNITION SWITCH
« 12R ACCESSORY TERMINAL
12R f
AMMETER
LEGEND:
AIR COND WIRING (PART OF
ENGINE WIRING HARNESS)
WIRING IS PART OF EQUIP
REG PRODUCTION WIRING
Fig.
119—Corvette—Four-Season Wiring Diagram
CHEVROLET CHASSIS SERVICE MANUAL
CORVETTE BODY
1B-6
ASH TRAY
SET SCREW
(PART
OF
KNOB)
TENSION
ADJUSTING
SCREWS
Fig.
8—Console Trim
cracks",
the
windshield opening must
be
carefully
checked
for
irregularities
and
deformation.
To
check
windshield opening proceed
as
follows:
1.
With weatherstrip
and all
foreign material removed
from perimeter
of
opening and with molding clips
in
place, install windshield checking blocks (Special
Tool J-8942)
as
shown in Figure 17. Note that check-
ing blocks must
be
placed over molding clips
to
obtain proper alignment.
2.
Place
a new
windshield glass
in
opening, resting on
J-8942 blocks
as
shown in Figure
18.
3.
Check
fit of
glass carefully. Space between glass
and frame should not vary more than 1/8".
4.
Mark
and
repair
any
imperfections. Recheck
fit as
required.
Fig.
9—Special Clip
Fig.
10—Sun Visor and Inside Rear View Mirror
Installation
1.
Carefully clean
all
loose material
out of
windshield
frame
(fig. 19).
2.
Install
new
molding clips (Item
9, fig. 12).
Both
models
use 13
type
B
clips equally spaced on lower
frame section.
37
Models use 11 type A clips equally
spaced on the top frame section.
3.
Apply
a
bead
of gun
grade body sealer such
as
3M-1170
in
apex
of
windshield frame
as
shown
in
Figure
20.
4.
Install weatherstrip on windshield glass.
5. Starting
at
bottom center
of
glass, insert
a
piece
of
heavy cord such
as
chalk line,
etc. in
groove
of
weatherstrip.
Cut
cord long enough so that about 10"
of free length exists after going around windshield.
Knot ends
of
cord together where they meet at bot-
tom center
of
glass
and
draw knot into groove
(fig.
21).
Tape loose ends
to
inside surface
of
glass
as
shown.
6. Place weatherstrip windshield assembly
in
wind-
shield frame. From inside
of
vehicle grasp ends
of
cord and pull toward you.
It is
wise to have an assis-
tant exert gentle
but
firm pressure
on
outside sur-
face
of
glass
in the
area where string
is
emerging
from weatherstrip. Figure
22
illustrates action
of
string
on
weatherstrip.
Lip of
seal
is
pulled out of
frame apex and over pinchweld flange.
7. When string
has
been removed, carefully inspect
seating
of lip
over entire perimeter
of
windshield,
paying particular attention to corners.
8. Apply
2
beads
of
sealer on outer surface
of
weather-
strip
as
shown
in
Figure
23.
Inject
a
moderate
quantity
of
windshield cement such
as
3M-6699B
between windshield glass
and
weatherstrip using
pressure gun
as
shown
in
Figure
23.
9. Install lower reveal molding, aligning
it
with mark
made upon disassembly. Refer
to
Figure
12,
View
A, before attempting installation; note that flange
of
molding
and
clips (item
9) at
ends
of
molding must
pass between molding retaining clips and windshield
frame.
li
difficulty
is met in
engaging molding
flange with retaining clips,
a
piece
of
shim stock
may
be
used
as a
"shoe horn"
to
place flange be-
hind clips.
10.
Install
in
order named: Upper reveal molding (align-
ing marks made
at
disassembly); side weatherstrip
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL 6M-8
^T^l^^/'-vN
COVER
BOTTOM
Fig. 1A—Polyurethane Element Air Cleaner
OIL RESISTANCE
SEAL
BOTTOM
BONDED PAPER
ELEMENT
COVER
Fig. 2A—Paper Element Air Cleaner
SERVICE
PROCEDURES
POLYURETHANE ELEMENT
Maintenance
1.
Remove cover wing nut, cover and filter element.
2.
Visibly check the element for tears or rips and re-
place if necessary.
3.
Clean all accumulated dirt and grime from air
cleaner bottom and cover. Discard air horn to air
cleaner gasket.
4.
/Remove support screen from element and wash
element in kerosene or mineral spirits; then squeeze
out excess solvent (fig. 3A).
NOTE: Never use a hot degreaser or any sol-
vent containing acetone or similar solvent*
5.
Dip element into light engine oil and squeeze out
excess oil.
NOTE: Never shake, swing or wring the ele-
me.nt to remove excess oil or solvent as this
may tear the polyurethane material. Instead,
"squeeze" the excess from the element.
6. Install element'on screen support (fig. 4A).
7.
Using a new gasket, replace air cleaner body over
carburetor air horn.
8. Replace the element in the air cleaner. Care must
be taken that the lower lip of the element is properly
placed in the assembly and that the filter material
is not folded or creased in any manner that would
cause an imperfect seal. Take the same precautions
when replacing the cover that the upper lip of the
element is in proper position.
9.<•
Replace cover and wing nut.
OIL BATH
Maintenance
L Remove air cleaner assembly.
2.
Remove cover and filter element assembly.
Empty oil out of
accumulated dirt.
cleaner and clean out all oil and
Fig. 3A—Cleaning Polyurethane Element
Fig.
4A—Polyurethane Support
CHEVROLET CHASSIS SERVICE MANUAL