ENGINE-ELECTRICAL 6Y-9
63 AMP 1
MODELS ONLY'
BATTERY FUSIBLE
LINK
HORN
FUSIBLE LINK'
TRANSISTOR
FUSIBLE LINK'
Fig.
4c— Circuitry - Voltage Regulator Assemblies (Corvette)
Engine compartment wiring harness incorporates sev-
eral fusible links. Each link is identified with its gage
size. A fusible link is a length of special wire (normally
four wire gages smaller than the circuit it is protecting)
used in wiring circuits that are not normally fused, such
as the ignition circuit. The same size wire with a hypalon
insulation must be used when replacing a fusible link.
The links are:
1.
The pigtail lead at the battery positive cable (except
Corvette) is a 14 gage, brown fusible link protecting
the 10 gage battery charging circuit. This wire is an
integral part of the battery cable assembly and serv-
icing requires replacing the complete battery cable
assembly. On Corvette models this link is installed
as a molded splice at the solenoid "Bat" terminal
and servicing requires splicing in a new link.
2.
A 16 gage black fusible link is located at the horn
4.
relay to protect all unfused wiring of 12 gage or
larger. It is installed as a molded splice and serv-
icing requires splicing in a new link.
The generator warning light and field circuitry (16
gage wire) is protected by a fusible link (20 gage
orange wire) used in the "battery feed to voltage
regulator #3 terminal" wire. The link is installed as
a molded splice in the generator and forward lamp
harness and is serviced by splicing in a new 20 gage
wire as required.
The ammeter circuit on all models is protected by
two orange, 20 gage wire fusible links installed as
molded splices in the circuit at the junction block or
the solenoid "Bat" terminal (Corvette only) and at
the horn relay. Each link is serviced by splicing in a
new 20 gage wire as required.
MAINTENANCE AND ADJUSTMENTS
At regular intervals, inspect the terminals for cor-
rosion an4 loose connections, and the wiring for frayed
insulation. Check mounting bolts for tightness. Check the
drive belt for alignment, proper tension and wear. Be-
cause of the higher inertia and load capacity of the rotor
used in A.C. generators, PROPER BELT TENSION is
more critical than on D.C. generators.
Since the Delcotron and its companion regulator are
designed for use on negative polarity systems only, the
following precautions must be observed. Failure to ob-
serve these precautions may result in serious damage to
the charging system.
1.
When installing a battery, always make absolutely
sure the ground polarity of the battery, generator and
regulator is the same.
2.
When connecting a booster battery, make certain to
connect the correct battery terminals together.
3.
When connecting a charger to the battery, connect the
correct charger leads to the battery
%
terminals.
4.
Never operate the generator on an uncontrolled open
TO SOLENOID
BAT ACC RES. WIRE
Fig.
5c—Typical Wiring Diagram Showing Lead Connections
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-2
FJg.
1 - Fuse Panel Assembly
All power window and tailgate circuits require the igni-
tion switch to be "ON" to open or close the windows un-
like past model designs which were operated independ-
ently of the ignition switch.
The windshield wiper and washer switch is new in that
washer button in the center of the knob has been deleted
and its function will be accomplished by pushing the knob.
A set screw is used to retain the knob to the shaft.
In addition to fuses, the wiring harness incorporates
fusible links to protect the wiring. Links are used rather
than a fuse in wiring circuits that are not normally fused,
such as the ignition circuit. Fusible links in the Chevro-
let wiring are four gauge sizes smaller than the cable it
is designed to protect. The links are marked on the
insulation with wire gauge size because of the heavy insu-
lation which makes the link appear a heavier gauge than it
actually is.
Engine compartment wiring harness incorporate sev-
eral fusible links. Each link is identified with its gauge
size.
A fusible link is a length of special wire (normally
four wire gauges smaller than the circuit it is protecting)
used in wiring circuits that are not normally fused, such
as the ignition circuit. The same size wire with a spe-
cial hypalon insulation must be used when replacing a
fusible link.
The links are:
1.
The pigtail lead at the battery positive cable (except
Corvette) is a 14 gauge, brown fusible link protecting
the 10 gange battery charging circuit. This wire is
an integral part of the battery cable assembly and
servicing requires replacing the complete battery
cable assembly. On Corvette models this link is
installed as a molded splice at the solenoid "Bat"
terminal and servicing requires splicing in a new
link.
2.
A 16 gauge black fusible link is located at horn relay
to protect all unfused wiring of 12 gauge or larger.
It is a serviceable piece with an in-line connector
and is not integral with the wiring harness.
3.
The generator warning light and field circuitry (16
gauge wire) is protected by a fusible link (20 gauge
orange wire) used in the "battery feed to voltage
regulator #3 terminal" wire. The link is installed
as a molded splice in the generator and forward lamp
harness and is serviced by splicing in a new 20 gauge
wire as required.
4.
The ammeter circuit on all models is protected by
two orange, 20 gauge wire fusible links installed as
molded splices in the circuit at the junction block or
the solenoid "Bat" terminal (Corvette only) and at the
horn relay. Each link is serviced by splicing in a
new 20 gauge wire as required.
The wiring harnesses use a standarized. color code
common to all Chevrolet vehicles. Under the color code,
the color of the wire designates a particular circuit. The
harness title indicates the type of harness, single of mul-
tiple wire, and also describe the location of the harness.
The body harness is a flat, solid wire assembly and is
routed through the vehicle near the center of the body.
Composite wiring diagrams (figs. 104 thru 124) are in-
cluded at the end of this section.
MAINTENANCE AND ADJUSTMENTS
Maintenance of the lighting units and wiring system
consists of an occasional check to see that all wiring
connections are tight and clean, that the lighting units are
tightly mounted to provide good ground and that the head-
lamps are properly adjusted. Loose or corroded con-
nections may cause a discharged battery, difficult start-
ing, dim lights, and possible damage to generator and
regulator. Wire harnesses must be replaced if insulation
becomes burned, cracked, or deteriorated. Whenever it
is necessary to splice a wire or repair one that is bro-
ken, always use solder to bond the splice. Always use
rosin flux solder on electrical connections. Use insulat-
ing tape to cover all splices or bare wires.
When replacing wires, it is important that the correct
size be used. Never replace a wire with one of a smaller
size.
Each harness and wire must be held securely in place
by clips or other holding devices to prevent chafing or
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-21
2.
Remove ash tray, retainer attaching screws and
retainer.
3.
Remove Air Conditioning distributor
duct'
retaining
screws and duct.
4.
Remove heater and/or Air Conditioning control panel
assembly retaining screws and push panel assembly
from console.
NOTE:
If interference between control panel
and radio is encountered, loosen radio retaining
nuts.
5. Remove radio control knobs, bezels and retaining
nuts.
6. Disconnect radio wiring harness and antenna lead-in.
7. Remove radio rear brace attaching screw and re-
move ra(Jio from vehicle.
8. Remove ignition switch bezel nut using Tool J-7607
and push switch rearward.
9. Disconnect cigarette wiring connector.
10.
Remove cigarette lighter retainer and lighter as-
sembly from console.
11.
To install, reverse removal procedure.
Fig.
35 - Cigarette Lighter — Chevelle
CHEVROLET INSTRUMENTS AND GAUGES
INDEX
Page
General Description 12-21
Service Operations 12-22
Instrument Cluster........................ 12-22
Instrument Cluster Lamps 12-22
Printed Circuit .
* •
12-22
Speedometer 12-22
Speedometer Cable 12-23
Fuel Gauge 12-23
Page
Clock 12-24
Tachometer 12-24
Ammeter . . 12-24
Temperature Gauge 12-24
Oil Pressure Gauge 12-24
Oil Pressure Indicator 12-24
Generator Indicator 12-26
Temperature Indicator 12-26
GENERAL DESCRIPTION
The standard instrument cluster on all models contains
seven circular housings consisting of: a speedometer;
fuel gauge; oil pressure, generator and temperature indi-
cators; right and left directional signal indicators; brake
warning and high beam indicators; and includes a clock
on deluxe models. An optionally available instrument
cluster provides special instrumentation which includes
in addition to the speedometer and clock: a tachometer;
fuel, oil pressure, ammeter and engine temperature
gauges; which replace the standard fuel gauge and indi-
cator lights. The brake warning indicator is relocated
to the tachometer dial face and the high beam and direc-
tional indicators are positioned in the speedometer dial
face.
Instrument cluster removal is recommended before at-
tempting to service the printed circuit and gauges even
though some units may be accessible from behind the
cluster. Limited working space under the instrument
panel increases the possibility of electrical malfunctions
due to poor connections, and damaged or improperly in-
stalled printed circuit. The printed circuit is service-
able but not repairable and requires complete
replacement.
The brake warning light serves a dual purpose. It
functions as an indicator when the parking brake is ap-
plied and also warns if a malfunction (loss of hydraulic
pressure) should occur in the brake system. The two
separate switches, which provide the signal to operate the
indicator, are located at the parking brake support and in
the hydraulic brake line at the master cylinder. Service
of the brake pressure, differential switch unit at the
master cylinder is described in Section 5 of this manual.
All indicator and cluster illumihating lamps may be
replaced without removing the cluster from the vehicle.
The bulbs are installed in plastic holders which lock into
the cluster housing and make contact with the printed
circuit. An instrument lamp is used to illuminate the
ignition switch. A special fibre optic lucite wiring
transmits light from the lamp to the switch.
Regular maintenance is not required on the instrument
cluster or its components other than maintaining clean,
tight electrical connections, replacing defective parts and
keeping the speedometer cable properly lubricated.
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-22
SERVICE OPERATIONS
INSTRUMENT CLUSTER
Removal and Installation (Figs. 36 thru 40)
I. Disconnect battery ground cable.
2:
Remove four screws retaining instrument bezel to
top edge of instrument console. Disengage tabs on
bezel lower section from clips on instrument console
and remove bezel.
3.
Protect mast jacket to prevent scratching when re-
moving cluster assembly.
4.
Remove eight screws securing leading edges of in-
strument cluster to console and pull cluster forward
from console opening.
5. Reaching behind cluster disconnect speedometer ca-
ble,
chassis harness connector, clock and speed
warning device connections (if so equipped) at rear of
cluster.
NOTE:
On models- with gauge pack, disconnect
oil pressure line also.
6. When all disconnects are made, remove cluster as-
sembly from vehicle.
7. To install, position cluster assembly to console
opening and connect speedometer cable, chassis
harness connector and other electrical connections
as required.
8. Position cluster in console opening and install eight
retaining screws.
NOTE:
Make sure ground strap between
cluster case and center right lower attachment
is properly installed.
9. Engage tabs on instrument bezel with clips on con-
sole and position bezel in console opening, then in-
stall four retaining screws.
10.
Install speed warning device control attaching nut and
knob,
if so equipped.
II.
Connect battery ground cable and check operation of
cluster assembly.
Fig. 36 - Instrument Cluster Installation — Chevrolet
Fig. 37 - Speed Warning Device
INSTRUMENT CLUSTER LAMP REPLACEMENT
(Figs.
38 and 39)
1.
Rotate socket counterclockwise to remove from rear
of cluster housing.
2.
To remove bulb, if socket is black color, pull bulb
straight out. If socket is gray color, depress and
rotate bulb, then pull out.
3.
Install replacement bulb in socket, pressing inward
to lock in place.
4.
Insert socket into housing, with lugs entering notches
in case, and rotate clockwise to lock in place.
PRINTED CIRCUIT REPLACEMENT (Figs. 38 and 39)
1.
Remove instrument cluster as previously described
in this section.
2.
Remove all cluster illuminating and indicator lights
from cluster housing.
3.
Remove fuel gauge and clock terminal nuts securing
printed circuit to housing.
4.
Remove four hex head screws retaining printed cir-
cuit to the cluster housing and remove the printed
circuit. . .
5. To install, reverse removal procedure.
CAUTION:. The retaining screws and terminal
nuts are part of the grounding circuit and must
be installed to provide the proper ground con-
nections for the printed circuit.
SPEEDOMETER
REPLACEMENT
1.
Remove instrument cluster as previously described
in this section.
2.
Remove screws retaining rear cover to the cluster
assembly. Bend ground strap away from cover and
remove cover.
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-26
•
Low oil
pressure
• High engine temperature
• Defective wiring
or
switch
connector from sender
in block above starter
on
and
at
left front
of
distributor
on V-8
Sending Unit Replacement
1.
Disconnect wiring harness
unit terminal (located
L-6 engines
engines).
2.
Remove sender unit using Tool J-21757
or 12
point
socket, replace with
new
unit
and
check operation.
GENERATOR INDICATOR
1.
Ignition
on,
Engine
not
Running
and
Telltale Light
Off.
• Indicator bulb burned out, replace bulb.
• Open circuit
or
loose connection
in the
telltale
light circuit.
2.
telltale Light Stays
on
after Engine
is
Started.
If indicator light does
not go out at
engine idle
speed, refer
to
Charging Systems under Engine
Electrical, Section
6Y.
TEMPERATURE (COOLING SYSTEM) INDICATOR
The temperature indicator circuit consists
of two re-
motely located units, indicator gauge
and
engine sender
unit.
The
indicator gauge, located
in the
instrument
panel, consists
of a
red light which will indicate
an
over-
heated engine condition.
Engine Sender Unit Replacement
1.
Drain engine cooling system
to a
level below unit.
2.
Remove sender unit (located
in the
inlet manifold
near water pump housing
on V-8
engines and
in the
cylinder head near
an
exhaust port
oh L-6
engines)
and replace with new unit.
3.
Refill cooling system
and
check operation
of
unit.
CHEVELLE INSTRUMENTS AND GAUGES
INDEX
Page
General Description
* *
i2-26
Service Operations
12-26
Instrument Panel
12-26
Instrument Cluster.
12-26
Fuel Gauge and/or Ammeter
12-27
Clock,
i 12-27
Speedometer
12-27
Page
Speedometer Cable
.
. 12-27
Temperature Gauge
12-29
Oil Pressure Gauge
12-29
Indicator Lights.
. 12-29
Oil Pressure Indicator
12-29
Generator Indicator
. . 12-29
• Temperature Indicator
12-29
GENERAL DESCRIPTION
The Chevelle instrument cluster assembly consists
of:
a speedometer;
a
fuel gauge;
a
generator,
an
engine
tem-
perature and an
oil
pressure indicator lamp, and includes
a clock
on
deluxe models.
On
super sport models,
am-
meter, coolant temperature
and oil
pressure gauges
re-
place
the
appropriate indicator lights. Except
for the
speedometer,
all of the
indicator lamps, instruments
and
gauges
of
these clusters may
be
serviced without remov-
ing
the
instrument cluster assembly from
the
vehicle.
In addition
to the
instrument indicator lamps,
a
brake
warning lamp
is
included
in the
cluster
as
standard
equipment.
The
indicator
is
connected
to the
parking
brake
and
brake pressure differential switches
and
serves
a
dual function.
It
lights when the parking brake
is applied
and
also when
the
brake pedal
is
applied,
if a
malfunction should occur
in the
brake system
due to a
loss
of
hydraulic pressure. Servicing
of the
hydraulic
pressure differential switch
is
covered
in
Section
5 of
this manual.
Regular maintenance
is not
required on the instrument
cjLuster
or its
components other than maintaining dean
and tight electrical connections, replacing defective parts
and keeping
the
speedometer cable properly lubricated.
SERVICE OPERATIONS
INSTRUMENT PANEL ASSEMBLY
INSTRUMENT CLUSTER (Figs.
41
thru
44)
Removal
1.
Disconnect battery ground cable.
2.
Remove steering coupling bolt and disconnect steer-
ing shaft from coupling.
3.
Loosen mast jacket lower clamp.
4.
Remove
air
conditioning center distributor duct
(if
so equipped).
5. Remove radio rear support bracket screw.
6. Remove mast jacket upper support clamp and retain-
ing bolts from lower support (refer
to
Section
9,
Steering).
CAUTION: Cover mast jacket
and
parl
brake handle with
a
suitable material
to
prevc
scratching.
7.
Disconnect speedometer cable
at
rear
of
cluster
housing
and
speed warning control knob
at
panel
(if
so equipped).
8. Remove instrument panel retaining screws (nine
upper and five lower).
.
9. Working under the console remove four lower retain-
ing screws from instrument cluster housing.
10.
Pull instrument panel assembly from console and
lay
forward on mast jacket.
11.
Disconnect wiring harness, cluster lamps and wiring
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-29
Fig.
43b - Speed Warning Device
TEMPERATURE AND/OR OIL PRESSURE
GAUGE
1.
Disconnect battery ground cable.
2.
Remove ash tray and ash tray retainer.
3.
Disconnect A/C hose from the distributor duct.
4.
Disconnect wiring connectors and lamp bulbs from
rear of gauge.
5. Disconnect oil pressure pipe fitting from rear of oil
pressure gauge.
6. Remove (3) screws retaining gauge assembly to
cluster cover and disengage unit from cover.
7. Remove (4) retaining nuts and remove gauge from
template.
8. To install, reverse removal procedure.
INDICATOR LIGHT REPLACEMENT
To replace any indicator or cluster bulb, unsnap the
proper socket from rear of instrument cluster, remove
and replace bulb, and reinsert unit into rear of cluster
housing.
OIL PRESSURE INDICATOR
If the light does not come on when the ignition switch is
turned on, or if the light comes on and remains on after
the engine is started, one or more the following condi-
tions is indicated:
• Low oil pressure
• Defective wiring or switch
• High engine temperature
Switch Replacement
1.
Disconnect wiring harness connector from sender
unit terminal (located in block above starter on L-6
engines and at left front of distributor on V-8
engines).
2.
Remove sender unit using Tool J-21757, replace with
new unit, and check operation.
GENERATOR INDICATOR
Ignition on, Engine not Running and
Telltale Light Off
1.
Indicator bulb burned out, replace bulb.
2.
Open circuit or loose connection in the telltale light
circuit.
Telltale Light Stays on after Engine is Started
If indicator light does not go out at engine idle speed,
refer to' Charging Systems under Engine Electrical,
Section 6Y.
TEMPERATURE
(COOLING
SYSTEM)
INDICATOR
The temperature indicator circuit, consists of two re-
motely located units, indicator gauge and engine sender
unit. The indicator gauge on all models uses a single
red light to indicate an overheated engine condition.
Engine Sender Unit Replacement
1.
Drain engine cooling system to a level below unit.
2.
Remove sender unit (located in the inlet manifold
near water pump housing on V-8 engines and in the
cylinder head near an exhaust port on L-6 engines)
and replace with new unit.
3.
Refill cooling system and check operation of unit.
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-31
CHEVY II INSTRUMENTS AND GAUGES
INDEX
Page
Page
General Description -.....
12-31
Service Operations.
12-31
Instrument Panel
. 12-31
Instrument Cluster
12-31
Fuel Gauge
12-32
12-32
Clock,
Speedometer
12-34
Speedometer Catte
12-34
Indicator Lights
12-34
Oil Pressure Indicator
12-34
Generator Indicator
12-34
Temperature Indicator
12-34
GENERAL DESCRIPTION
The Chevy
n
instrument cluster assembly consists
of:
a speedometer;
a
fuel gauge;
a
generator, temperature
and
oil
pressure indicator lamps, and includes
a
clock
on
deluxe models. Except
for the
speedometer,
all of the
cluster lamps, instruments and gauges
of
the cluster
may
be serviced without removing
the
instrument cluster
as-
sembly from
the
console.
In addition
to the
instrument indicator lamps,
a
brake
warning lamp
is
included
in the
cluster
as
standard
equipment.
The
indicator
is
connected
to
thfc parking
brake and brake pressure differential switches andserves
a dual function.
It
lights when
the
parking brake
is ap-
plied
and
also when
the
brake pedal
is
applied,
if a mal-
function should occur
in the
brake system
due to a
loss
of
hydraulic pressure. Servicing
of the
hydraulic pressure
differential switch
is
covered
in
Section
5 of
this manaul.
Regular maintenance
is not
required on
the
instrument
cluster
or its
components other than r^Mfitftl^i^g clean
and tight electrical connections, replacing defective parts
and keeping
the
speedometer cable properly lubricated.
SERVICE OPERATIONS
INSTRUMENT PANEL
INSTRUMENT CLUSTER
Removal
and
Installation {Figs.
45
thru
48)
1.
Disconnect battery ground cable.
2.
Remove mast jacket upper support clamp (refer
to
Steering, Section
9, for
complete procedure
on low-
ering jacket) and lower steering column.
NOTE:
Apply protective material
to the
mast
jacket
to
prevent damage
to the
painted surfaces.
3.
Disconnect retaining collar securing speedometer
cable
to
speedometer head.
4.
Remove screws retaining cluster
to
console.
5. Pull cluster forward
of
console opening and discon-
nect
all
wiring
and
lamp connections. Remove
cluster from vehicle.
CAUTION:
Do not
pull cluster outward further
than slack
in
wiring harness will allow, other-
Fig.
45-
Instrument Cluster Installation
—
Chevy
II
Fig.
46 -
Speed Warning Device
CHEVtOtET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-36
CAMARO INSTRUMENTS AND GAUGES
INDEX
Page
General Description
12-36
Service Operations
12-36
Instrument Cluster
. . . 12-36
Instrument Lamps
12-36
Printed Circuit
12-36
Fuel Gauge
12-37
Tachometer
. . 12-37
Seat Separator Instrument Console
12-37
Page
Fuel Gauge
12-37
Ammeter
12-37
Temperature Gauge
12-37
Oil Pressure Gauge
. 12-37
Fuel Warning Unit
12-37
Clock.
... 12-37
Oil Pressure Indicator
12-37
Generator Indicator
12-38
Temperature Indicator
12-38
GENERAL DESCRIPTION
The standard Camaro instrument cluster assembly con-
sists
of two
circular units which house
the
speedometer
and fuel gauge assemblies.
The oil
pressure, left-hand
directional
and
brake warning indicators
are
located
in
the face
of the
speedometer bezel while generator,
tem-
perature
and
right-hand directional indicators are grouped
with
the
fuel gauge unit.
The
high beam indicator
is
located between
the
cluster bezels.
A special instrumentation package
is
available with
the
eight-cylinder engine
and
center floor console combina-
tion.
The
special cluster includes:
a
clock; coolant
temperature,
oil
pressure, fuel
and
ammeter gauges,
mounted forward
on the
seat separator console;
a ta-
chometer
in the
right circular housing
of the
dash
in-
strument cluster; and
a low
fuel level indicator replacing
the
oil
pressure indicator lamp
in the
instrument cluster.
The instruments
and
gauges,
may be
serviced only
after
the
instrument cluster
is
removed from
the
vehicle.
Indicator
and
cluster lamps except
for the
high beam
indicator
may be
replaced without removing
the
cluster
assembly. Partial cluster removal
is
necessary when
replacing
the
high beam indicator due
to its
proximity
to
the upper brace
rod
anchor plate.
The
bulbs
are in-
stalled
in
plastic sockets which lock into
the
cluster
housing and make contact with
the
printed circuit.
A
low
level fuel warning system
is a
special feature
available with
the
floor console gauge pack. This
sys-
tem includes
an
indicator lamp
in the
dash cluster and
a
semi-conductor unit senses
the
change
in
electrical
re-
sistance
of the
fuel system circuitry
as
variations
in
fuel level occur.
The
sensing device
is
replaced
as a
unit
if
found defective.
The brake warning light serves
a
dual purpose.
It
functions
as an
indicator when
the
parking brake
is ap-
plied
and
also
if
there
is a
malfunction (loss
of
hydraulic
pressure)
in the
brake system. Switches which provide
the signal
to
operate
the
light
are
located
at the
parking
brake assembly
and at the
brake master cylinder
in the
hydraulic lines. Service
of the
brake pressure differ-
ential switch unit
is
covered
in
Section
5 of
this manual.
Regular maintenance
is not
required on
the
instrument
cluster
or its
components other than maintaining clean,
tight electrical connections, replacing defective parts
and keeping
the
speedometer properly lubricated.
SERVICE OPERATIONS
INSTRUMENT CLUSTER (Figs.
50
thru
53)
Removal
and
Installation
1.
Disconnect battery ground cable.
2.
Remove mast jacket lower support screws
at toe
pan.
3.
Remove mast jacket upper support bolts
and
allow
steering wheel
to
rest
on
seat cushion.
CAUTION: Both supports must
be
detached
to
prevent distortion
of
mast jacket.
4.
Remove cluster attaching screws from face
of
panel
and partially remove assembly from console opening.
5. Reaching behind cluster assembly, disconnect speed-
ometer cable, speed warning device
(if so
equipped
-
Fig.
51) and
chassis harness connector
at
rear
of
panel.
6. Remove assembly from console opening to
a
suitable
bench area
for
required service operations.
7.
To
install, reverse removal procedure.
INSTRUMENT CLUSTER LAMP REPLACEMENT
1.
Turn bulb holder counterclockwise
and
pull
out to
remove from
the
cluster housing.
2.
Pull bulb straight out
to
remove from socket.
3.
Press replacement bulb inward
to
lock
in
socket.
4.
Insert lamp assembly into housing, with lugs
on
holder entering notches
in
housing,
and
turn clock-
wise
to
lock
in
place.
PRINTED CIRCUIT REPLACEMENT
1.
Remove instrument cluster
as
previously described
in this section.
2.
Remove
all
cluster illuminating and indicator lamps
from housing.
3.
Remove fuel gauge terminal nuts
or
tachometer
re-
taining nuts securing printed circuit
to
housing.
4.
Remove four
hex
head screws retaining printed
cir-
cuit
to the
cluster housing
and
remove circuit from
housing.
5.
To
install, reverse removal procedure.
CAUTION:
The
retaining screws
are
part
of
the grounding circuit
and
must
be
installed
to
provide proper connections
for the
printed
eir-
cuit.
CHEVROLET CHASSIS SERVICE MANUAL