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8-68
INSTRUMENTS
Condition
Possible Cause
Correction
SYSTEM DOES NOT
CANCEL AFTER COM-
PLETION OF TURN.
ENTIRE SYSTEM DOES
NOT OPERATE.
(b)
Faulty fuse.
(b)
Replace fuse.
PILOT LAMP ILLUMI-
(a) Loose or corroded external lamp ground
NATES BRIGHTLY, EXTER-
connection.
NAL LAMPS
GLOW
DIMLY WITH
NO
FLASH.
(a) Broken or loose cancelling finger.
(b)
Improperly aligned cancelling finger.
(c) Broken or faulty switch.
(a) Open circuit in feed wire to switch.
(a) Replace cancelling finger.
(b)
Align cancelling finger properly.
(c) Replace switch.
(a) Test wiring circuits.
(a) Clean and tighten ground connection.
Models A V - I , AV-2, AR-I and AR-2
The instrument cluster assembly is attached to the
instrument panel by four cross-recessed screws. The
cluster contains the speedometer, fuel gauge, tem-
perature gauge, alternator (ammeter), oil pressure
warning light and clock (if so equipped). The instru-
ments and lamps are attached to a printed circuit
board in which are imbedded the electrical circuits
(conductors) in the form of die cut, copper foil strips.
The printed circuit completes the circuit to the fuel
gauge, temperature gauge, voltage limiter and instru-
ment lamps. The screws attaching the printed circuit
board to the cluster base serve as a ground for the
instrument lamps and the voltage limiter.
With the exception of the leads to the alternator
(ammeter) and clock, all wiring to the cluster
is
con-
nected through a plug type multi-connector to the
male connector pins on the printed circuit board
which is mounted to the back of the instrument clus-
ter assembly. The female multi-connector is a push
type with a master locator pin.
The fuel and temperature gauges are the thermal
type. The gauges operate on a principle of a constant
voltage being applied and are sensitive to changes in
fuel level or temperature.
Models AP-I and AP-2
The instruments and gauges are contained in two
groups or clusters mounted on the instrument panel
in front of the driver. The cluster above the steering
column contains the speedometer, turn signal indi-
cators and the necessary cluster illumination bulbs.
The cluster to the left of the steering column con-
tains the alternator (ammeter) gauge, fuel and tem-
perature gauges and the oil pressure indicator lamp.
The clock
(if
so equipped)
is located on the instru-
ment panel in line with the radio. The gauges are the
thermal type and are sensitive to changes in fuel level,
temperature of the engine coolant and engine oil pres-
sure respectively.
SERVICE PROCEDURES
VOLTAGE LIMITER
Models A V - I , AV-2, AR-I and AR-2
Constant voltage
is
provided to the gauges through
the use of a voltage limiter mounted on the back of
the instrument cluster printed circuit board and
is
connected in parallel to the gauges and provides the
same regulated voltage to the gauges.
Models AP-I and AP-2
Constant voltage is provided through a voltage lim-
iter contained inside the fuel gauge. The voltage lim-
iter
is
connected in parallel to the gauges and pro-
vides the same regulated voltage to the gauges.
Testing the Voltage Limiter-
in the Vehicle
A quick test to determine
if
the voltage limiter
is
operating is to connect one lead of a voltmeter or
test lamp to the temperature sending unit and the
other lead to a good ground; leave the sending unit
lead wire attached to the sending unit.
Turn the ignition switch to the
"on8'
position. A
fluctuating voltmeter or a flashing lamp indicates the
voltage limiter is operating.
Testing the Voltage Limiter-Instrument
Cluster Removed
Models A V - I , AV-2, AR-I and AR-2
Connect a jumper wire from the positive post of a
12
volt test battery to the voltage limiter input ter-
minal. Connect another jumper wire from the battery
negative post to the voltage limiter case (ground).
Connect the negative lead of a voltmeter to the
battery negative post. Touch the positive lead of the
voltmeter to the input terminal of the voltage limiter.
A reading of 12 volts should be shown on the volt-
meter.
Touch the positive lead of the voltmeter to the out-
put terminal of the voltage limiter. A fluctuating read-
ing between
0
and
7
volts should be shown on the
voltmeter. Any other reading indicates the voltage
limiter
is
not functioning properly and should
be
re-
placed.
Models AP-I and AP-2
Connect a jumper wire from the positive post of a
12 volt test battery to the "I" terminal of the fuel
gauge. Connect another jumper wire from the battery
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