Engine wiring CHEVROLET CAMARO 1967 1.G Chassis Owner's Guide

ELECTRICAL-BODY AND CHASSIS 12-8

is inserted through radiator support opening.

Remove two screws retaining lamp assembly to

lower sheet metal.

Remove three screws retaining lamp assembly to

lender.

To replace lamp assembly, reverse removal proce-

dure and check operation of the unit.
is aligned with flat on pivot shaft. Install stop lock

bolt and torque bolt to 45-60 in, lbs. Make sure that

side-to-side panel alignment is not changed when in-

stalling and tightening the stop.

CAUTION: Do not exceed specified torque

when tightening stop lock bolt.

HEADLAMP PANEL REPLACEMENT-CORVETTE

Refer to Figure 13 for Panel Mounting details.

1.
Remove engine compartment hood as outlined in

Section 1.

2.
Actuate headlamp panel to the open position.

NOTE:
In the event headlamp motor is inop-

erative, manual positioning of the panel can be

accomplished by turning the knurled knob at in-

board end of motor. As an assist in manual

operation of panel, apply light hand pressure to

panel in desired direction of rotation.

3.
Remove positive lead from battery terminal.

4.
Remove headlamp bezel retaining screws and bezel.

5. Remove the sealed beam housing unit as an assem-

bly - disconnect sealed beam leads at harness con-

nector and remove connector from sealed beam

leads;
remove the housing-to-panel retaining screws

and remove housing unit and wiring from panel.

6. Remove motor from panel pivot shaft - see motor

removal procedure. Then remove the panel stop

from panel inboard pivot shaft, and disconnect switch

lead wires from panel, support-mounted motor

switch.

7. Remove the panel retaining bolt access hole plugs

from inside the panel then rotate panel as required

and remove the retaining bolts and slide supports

from ends of panel pivot shaft. Remove bearing, felt

seal, retainer and washer from inboard pivot shaft.

8. Remove panel from its location by alternately disen-

gaging pivots from their retaining slots and with-

drawing unit forward through opening in body (fig.

14).

9. Loosen alien screw in spacer and disassemble parts

from the panel outboard pivot shaft.

10.
Install washer, retainer, felt seal, bearing and

spacer, in that order, to panel outboard pivot shaft.

Do not tighten spacer on shaft at this time.

11.
Position panel in body opening and index panel pivot

shafts in retaining slots; then loosely install support

retaining bolts.

12.
Install washer, retainer, felt seal, bearing and sup-

port, in that order, to panel inboard pivot shaft, and

loosely install support retaining bolts. -

13.
Check side-to-side alignment of panel, making sure

that there is no panel-to-body contact; position

spacer snugly against bearing; then tighten spacer

seat screw to 30-50 in. lbs.

14.
Install stop on panel inboard shaft so that it rests

against bearing, being sure that index mark on stop
15.
Check and align panel to body as follows:

a. Tighten panel pivot support bolts snugly but still

allowing panel to" be moved by applying hand

pressure.

b.
Position panel to the closed position and align

with body so that all surfaces are flush.

c. With the panel in the closed position the outboard

access hole is aligned with the forward bolt head.

Tighten this bolt with the panel in the closed

position - access to bolt head can be obtained by

working through opening between the hood and

body.

d. Rotate panel to obtain access to each bolt head

and torque bolts to 100-140 in. lbs.

e. Connect switch lead wires to support-mounted

limit switch.

16.
Install seaLed beam housing unit and at the same time

position sealed beam lead wires through panel out-

board pivot shaft. Install housing unit retaining

screws and install lead wires in connector, making

sure to match colors between harness and connector.

17.
Install motor assembly - see motor replacement

procedure.

18.
Connect positive lead to battery terminal.

19.
Adjust headlamp panel as outlined under "Headlamp

Panel Travel Adjustment".

20.
Adjust headlamp aiming as outlined under "Headlamp

Adjustment".

21.
Install headlamp bezel and engine compartment

hood - refer to Section 1 for hood installation.

Fig.
14
- Headlamp Panel Removal (Corvette)

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 12-24

1.
Temperature Gauge

2.
Instrument Cluster Lamp

3.
R.H. Directional Indicator

4.
Ammeter Gauge
Fig. 39- Optional Gauge Cluster

5. Fuel Gauge

6. L.H. Directional Indicator

7. Tachometer

8. "Brake" Indicator

9. "Bright" Indicator
10.
Oil Pressure Fitting

11.
Chassis Harness Connector

12.
Clock Assembly

13.
Printed Circuit

NOTE:
Observe carefully the stack up of the

internal parts of the fuel gauge assembly.

5. To install, reverse removal procedure.

CLOCK OR TACHOMETER REPLACEMENT

NOTE:
The tachometer is a self-contained, all

transistor unit requiring very little service

other than keeping the terminal nuts clean and

tight. The unit is not serviceable and must be

replaced, if defective.

1.
Remove instrument cluster as previously described

in this section.

2.
For clock replacement, remove clock set shaft knob

at front of console.

3.
Remove cluster lamps from cover, circuit attaching

screws, and terminal nuts at circuit to gauge attach-

ing points.

4.
Move printed circuit away from gauge and remove

screws retaining
•_
gauge or clock to the cluster

housing.
•5.
Remove unit, from housing and cover plate from

gauge unit.

6/To install, reverse removal procedure.

AMMETER TEMPERATURE AND OIL PRESSURE

GAUGES REPLACEMENT

1.
Remove instrument cluster as previously described

iii this section.

2.
Remove instrument lamps, attaching screws or nuts

and wiring connections as required.

3.
Remove gauge assembly backing plate retaining

screws and remove gauge assembly from cluster

housing.

4.
Remove terminal nuts and/or screws retaining gauge

to the backing plate and separate plate from the

gauge.
•

5. To install, reverse removal procedure.

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 of the following condi-

tions is indicated:

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 12-34

5. To replace, reverse the removal procedure.

SPEEDOMETER REPLACEMENT

1.
Remove instrument cluster as previously described

in this section.

2.
Remove clock set shaft knob.

3.
Remove eight screws securing cluster housing to

bezel trim panel. Separate parts carefully observing

stack up of parts.

4.
Remove two screws securing speedometer head to

rear of cluster housing.

NOTE:
Servicing of the speedometer head

should be performed by an authorized AC Speed-

ometer Service Station.

5. To install, reverse the removal procedure..

SPEEDOMETER CABLE

Replacement or Lubricatibn

1.
Disconnect the speedometer cable from the speed-

ometer head. Remove the old cable by pulling it out

from speedometer end of conduit.

NOTE:
If old cable is broken it may be neces-

sary to remove lower piece from transmission

end of conduit.

2.
Lubricate the lower 3/4 of cable with speedometer

cable lubricant and push the cable into the conduit.

Connect the upper end to the speedometer head and

road test vehicle for proper speedometer operation.

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 of the following

conditions is indicated:

• Low oil pressure

• High engine temperature

• Defective wiring or switch

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, replace with new unit, and

; check operation.

GENERATOR INDICATOR

1.
Ignition on, engine not running and telltale light off.

a. Indicator bulb burned out, replace bulb.

b.
Open circuit or loose connection in the telltale

light circuit.

2.
Telltale light stays on after engine is started.

a. 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.

CORVETTE INSTRUMENTS AND GAUGES

INDEX

Page

General Description ., 12-34

Service Operations . 12-35

Instrument Cluster ., 12-35

Fuel Gauge 12-35
Speedometer/Tachometer Service. 12-35

Temperature Gauge 12-35

Ammeter/Oil Pressure Gauges 12-35

GENERAL DESCRIPTION

All Corvette instruments and gauges are conveniently

located in the dash-mounted cluster. The entire cluster

is removable to permit servicing of the various instru-

ments and gauges. The indicator and cluster illuminating

bulbs may be replaced without removing the cluster from

the panel.
Regular maintenance is not required on the instrument

cluster or its components other than maintaining clean

and keeping the speedometer and tachometer cables

properly lubricated.

CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-37

Fig.
50 - Instrument Cluster Installation — Camaro

FUEL GAUGE REPLACEMENT

1.
Remove instrument cluster assembly as previously

described.

2.
Remove cluster lamps from gauge cover plate,

ground screw and terminal nuts attaching printed

circuit to fuel gauge.

3.
Remove three screws retaining gauge assembly to

cluster housing.

4.
Carefully move printed circuit away from gauge and

remove gauge assembly from cluster housing.

5. Remove terminal nuts securing gauge to cover plate,

and detach gauge unit.

6. To install, reverse removal procedure.

TACHOMETER

NOTE:
The tachometer is a self-contained, all

transistor unit requiring very little service

other than keeping the terminal nuts clean and

tight. The unit is not serviceable and must be

replaced, if defective.

1.
Remove instrument cluster as previously described

in this section.

2.
Remove cluster lamps from rear of gauge cover and

disconnect harness wiring connections from gauge

terminals.

3.
Remove three screws retaining gauge to cluster

housing.

4.
Move printed circuit away from gauge area and re-

move gauge unit from housing.

5. Remove terminal nuts securing gauge to cover

detach unit.

6. To install, reverse removal procedure.

SEAT SEPARATOR INSTRUMENT CONSOLE

(Fig.
54)
(Fuel,
Ammeter, Temperature, Oil Pressure Gauges,

Low Fuel Warning Unit, and Clock)

1.
Disconnect battery ground cable.

2.
Remove clock shaft knob from face of cluster.

3.
Remove cover retaining screws (4) and cover from

cluster assembly.

NOTE:
Use an alien wrench to remove the two

screws located in the top of the cover below the

instrument console.

4.
Remove four screws retaining gauge mounting plate

to cluster housing.

5. Carefully disengage gauge plate from housing and

disconnect oil pipe and all electrical connections at

rear of gauges.

NOTE:
At this point, with gauge package re-

moval from housing all gauges including the low

fuel warning system may easily be serviced.

6. To install assembly, use reverse of removal

procedure.

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 of the following

conditions is indicated.

• Low oil pressure

• Defective wiring or switch

Sending Unit 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).

Fig.
51 - Speed Warning Device

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-9

Adjustment- Adjust the bead chain so that it is as tight

as possible without holding the throttle open when the

carburetor is set at its lowest idle throttle position.

When connecting the bead chain (engine stopped) manually

set the fast idle cam at its lowest step and connect the

chain so that it does not hold the idle screw off the cam.

If the chain needs to be cut, cut it three beads beyond the

bead which pulls the linkage.

REGULATOR

Service - A defective regulator, that is one which is not

simply out of adjustment, must be replaced. During re-

placement, check the hoses which connect to the regulator

and replace any which are cracked or deteriorated.

Air Filter

The air filter located in the solenoid cover should be

cleaned and re-oiled at engine oil change intervals.

1.
Snap the solenoid cover off.

2.
Remove the filter and wash it in kerosene or mineral

spirits. Squeeze it dry and wet with SAE 10 engine

oil.
Squeeze out excess oil and reinstall into the

cover.

3.
Attach the cover with neoprene seal to the solenoid

housing. Be certain that the cover fits tightly to the

housing.

One regulator adjustment is possible: Engagement-

Cruising Speed Zeroing (to remove any difference be-

tween engagement and cruising speed).

NOTE:
No regulator adjustment should be

made, however, until the following items have

been checked or serviced:

1.
Bead chain properly adjusted.

2.
All hoses in good condition, properly attached, not

leaking, not pinched or kinked.

3.
Regulator air filter clean and properly oiled.

4.
Electric and vacuum release switches properly

adjusted.

Engagement—Cruising Speed Zeroing

If the cruising speed is lower than the engagement

speed, loosen the orifice tube locknut and turn the tube

outward; if higher, turn the tube inward. Each 1/8 turn

will alter the engagement-cruising speed difference one

mph. Tighten the locknut after adjustment and check the

system operation at 50 mph.

ELECTRICAL SYSTEM CHECK OUT

1.
Check fuse and connector.

2.
Check electric brake switch as follows: Unplug con-

nector at brake switch. Connect ohmmeter at points

A and B on brake switch. The ohmmeter must indi-

cate infinity when the brake pedal is depressed and

continuity when pedal is released. The cruise re-

lease brake switch (electric) is adjusted as is the

standard stop light brake switch. Replace electric

brake switch if needed.

3.
Check engagement switch and connecting wiring as
follows: Unplug push button control connector

(brown, blue, black) at electrical wiring harness con-

nector and perform the following tests. (See Fig-

ure 10)

Test #1
—
Connect ohmmeter between terminal #1 (brown

wire) and terminal #2 (blue wire). Continuity shall be

maintained until switch is depressed all the way in.

Test #2
—
Connect ohmmeter between terminal #1 (brown

wire) and terminal #3 (black). No continuity shall be

shown; however, when the button is depressed halfway,

continuity shall be indicated. When the button is pressed

all the way down, no continuity shall be shown.

Test #3 — Connect ohmmeter between terminal #2 (blue

wire) and terminal #3 (black). Button released, no con-

tinuity; however, when the button is depressed partially

and fully, continuity shall be shown.

4.
Check regulator solenoid coil, low-speed switch, and

wiring harness as follows:

a. Disconnect engagement switch wire harness con-

nector from the main wire harness connector

(brown, blue, and black wires). Connect ohm-

meter
'
between point C (blue wire in main wire

harness) and ground. (Make sure the regulator is

well grounded to chassis.) The ohmmeter should

read 45 ohms ± 2 ohms. If a resistance of

greater value is shown, then disconnect the con-

nector from the regulator and measure the re-

sistance of the blue wire from point C to D. It

should measure 40 ohms. Check the resistance

from point E (vertical bar of terminal forming T)

to ground. It should measure 5 ohms ± 1/4 ohm.

Replace either the wiring harness or solenoid as

needed if greater values are indicated. The black

harness wiring from point F to G should also be

checked for continuity.

ENGAGEMENT SWITCH TEST

BUTTON POSITION

Cruise (released)

Engage (partially depressed)

Trim (fully depressed)
TERMINALS

1 TO 2

closed

Closed

open
1 TO 3

open

closed

open
2 TO 3

open

closed

closed

SERVO AND VACUUM SYSTEM CHECK OUT

To determine the condition of the diaphragm, remove

hoses from power unit and apply 14 inches of vacuum to

either vacuum tube opening (seal the other opening) and

hold in for one minute. The vacuum shall not leak down

more than 5 inches of vacuum in one minute. If leakage

is detected, replace servo. To utilize engine as a vac-

uum source, proceed as follows:

1.
DISCONNECT SERVO $EAD CHAIN and hoses from

servo and connect engine vacuum directly to vacuum

servo fitting (fitting in middle of servo). Seal the

servo unit opening.

2.
Note position of servo diaphragm.

3.
Start engine - the diaphragm should pull in.

4.
Clamp off engine vacuum supply line and check for

leakage. '

The cruise release brake switch (vacuum) and connecting

hoses can likewise be checked using a vacuum pump.

CHEVROLET CHASSIS SERVICE MANUAL