1984 NISSAN 300ZX Electrical System Workshop Manual

METER AND GAUGES - Digital Type Combination Meter
Trouble-st
Torque meter does not operate
1 Go to "Display Check" I
Go to "Power Unit Check"
v
Replace meter Replace
and gauge assembly power unit
I
I Check boost sensor circuit I
boost sensor and meter boost
sensor
1 Disconnect meter harness connector
2 Connect vacuum pump gauge to boost
3
4
(white)
sensor vacuum hose
Turn the ignition switch to "ON"
Apply vacuum pressure to boost sensor by
vacuum pump gauge and measure voltage
across
0 and
Vacuum -
~eep harness connected
J wu 1 3v at-53 3kPa 1-400 mmH
SEL667 Voltmeter -15 75 mHg) '
rg (Cont'd)
Main fuel gauge does not operate
I
Go to "Display Check"
Go to "Power Unit Check"
Replace meter Replace
and gauge power unit
assembly
Check fuel tank main gauge clrcult
I OK
Replace meter
and gauge
assembly Go to "Fuel tank
gauge check"
.
Check harness between Replace fuel
fuel tank gauge and meter
tank gauge unit
1 Disconnect meter harness Connector
(black)
Turn ignition switch to
"OFF" 2
3 Measure resistance between @ and @
e

Ohmmeter SEL6680
EL-49

METER AND GAUGES - Digital Type Combination Meter
Trouble-shooting (Cont'd)
Fuel residue
Sub fuel gauge (digital display1 does not operate
Go to "Display Check"
Go to "Power Unit Check"
Replace meter Replace
and gauge power unit
assembly
Resistance
Check harness
Check fuel tank sub gauge circuit
Go to "Fuel Tank
Gauge Check"
OK
v T
Replace Check harness between Replace meter
fuel tank fuel tank gauge and meter and gauge
gauge unit assembly
FUEL INJECTION PULSE CIRCUIT
CHECK
1 Disconnect meter harness connector
(black)
2. Turn ignition switch to "ON"
3 Check for voltage across @$ and 0.
Voimeter SE L669 t
FUEL TANK SUB GAUGE CIRCUIT
CHECK
1 Turn ignition switch to "OFF"
2. Measure resistance between 0 and 0.
Ohmmeter
Ignition switch- OFF
More than ZOQ Less than 4R
SEL670D
EL-50

METER AND GAUGES - Digital Type Combination Meter
Trou ble-sho
Go to "Display Check"
OK
Go to "Power Unit Check"
T
Replace meter and
gauge assembly Replace power unit
T Replace meter and gauge assembly
ng (Cont'd)
Only water temp gauge does not operate
I
Go to "Display Check"
T
OK
Replace meter and
gauge assembly
Check water temp sensor (thermistor) Circuit
OK NG
Replace meter
and gauge
assembly
Check harness between Replace
thermistor and meter thermistor
1 Disconnect meter harness connector
2
3
(black)
Turn ignition swltch to "OFF"
Measure resistance between 0 and @
!'W I 1 Ohmmeter
ignition switch - OFF
Resistance
70CI or more
6O'C or more Approx 10 - 70R
SEL6710
EL-51

METER AND GAUGES - Digital Type Combination Meter
Trouble-shooting (Cont’d)
Go to “Displav Check”
ING OK
Replace meter and
gauge assembly
v
Check oil pressure sensor circuit
OK NG
Go to “Oil Pressure
Sensor Check” Replace meter
and gauge
assembly
Check harness between Replace oil
oil pressure sensor and meter pressure
sensor
1 Disconnect meter harness connector
(black)
2 Measure resistance between @ and @
when engine stopping and running
Ohmmeter
Engine Resistance
Approx 75R or more
Idling Approx 60R or less
SEL672D
“Trip”, ”Ave speed” and “Dist to empty” meters
1 Go to ”Display Check” 1
Go to “Power Unit Check”
Replace trip Replace power unit
meter assembly
Only “Ave speed” meter does not operate
I
I Go to “Display Check“ I
lNG
OK
Replace trip
meter assembly
I Check clock for proper operation I
Check harness between Replace clock
clock and meter
I OK v
Replace trip meter assembly

METER AND GAUGES - Digital Type Combination Meter
Power Unit Check
Voltmeter
terminal
(f) (-)
E -
-%; 0
0
@I
__
@
9
0
0
Remove power unit with harness connected
Perform voltage and continuity tests Refer to
chart below
I Voltage
[VI
Approx 12
Approx 5
Approx 16
Approx 5
Approx 22
Approx 285
Turn ignition switch to "ON"
1 - 1 More than 6
Remarks
Check when no
display appears
For speedometer
For tachometer
For Temp,
Oil, Volt
sause
For Fuel gauge
For "Trip", "Ave
speed"
& "Dirt to
empty" meter
Turn ignition switch to "OFF"
Ohmmeter
Continuity Remarks
Check when no
ground display appears
If specified voltage or continuity is not produced,
replace power unit.
- Boost Sensor Check
1 Connect vacuum pump gauge to boost sensor
vacuum hose
2 Disconnect harness connector from boost
sensor and connect battery and voltmeter
as
shown
3 Apply vacuum pressure to boost sensor by
vacuum pump gauge and measure voltages
Approx.
2.2V at 0 kPa (0 mmHg, 0 inHg)
(Atmospheric pressure)
Approx.
1 3V
at -53.3 kPa (-400 mmHg, -15 75 inHg)
vacuum pump gauge
SEL674D
EL-53

METER AND GAUGES - Digital Type Combination Meter
Speed Sensor Signal Check
SPEED SENSOR OUTPUT CHECK
When speedometer
is functioning properly, this
test
is not necessary. Go to "Meter Output check"
1 Remove cluster lid A
2 Connect a voltmeter between @ and @ on
cornbination meter side. Combination meter
harness connector should remain connected to
instrument harness
Switch ignition switch from "OFF" to
"ON"
Voltmeter should indicate approximately 5
volts when switch is "ON"
If voltmeter indicates no voltage, go to "Power
Unit Check".
3
SEL745D
4
5
Turn ignition switch to "OFF"
Disconnect speedometer cable from speed
sen-
sor and remove speed sensor with harness con-
nected.
6. Disconnect combination meter harness from
instrument harness
as shown below, and con-
nect
a voltmeter across @ and @
Voltmeter SEL746D
7
8
Turn ignition switch "OFF" + "ON"
Slowly turn speed sensor rotor shaft with a
suitable screwdriver to make sure voltmeter
pointer deflects
Do not turn rotor shaft quickly as voltmeter
deflects
24 times per revolution of rotor shaft
SEL747D
If voltmeter pointer does not deflect, replace speed
sensor.
EL-54

METER AND GAUGES - Digital Type Combination Meter
Speed Sensor Si!
METER OUTPUT CHECK
Combination meter emits speed sensor signal to
control
E C.C.S. control unit, A.S.C D. control
unit, voice warning
unit and AIT control unit.
Disconnect speedometer cable from speed sen-
sor and remove speed sensor with harness con-
nected 1
2 Remove cluster lid A.
3 Disconnect combination meter harness from
instrument harness
as shown, and connect an
ohmmeter between @ and 0
Ohmmeter
SEL748D
11 Check (Cont'd)
4
5
Turn ignition switch "OFF" + "ON".
Slowly turn speed sensor rotor shaft with a
suitable screwdriver to make sure ohmmeter
pointer deflects.
Ohmmeter pointer deflects twice for each rotatton
of rotor shaft
Ohmmeter -
SEL7490
If ohmmeter pointer does not deflect, go to
"Speed Sensor Output Check". (Refer to back
paw)
EL-55

METER AND GAUGES - Digital Type Combination Meter
Fuel Tank Gauge Check
For removal, refer to FE section
Ohmmeter terminal Float
Main gauge
Resistance value
Approx 10 - 20Q
Approx 480 - 520Q
Approx 100 - 1 1 OQ
Approx 4Q or below
Approx
870.930Q
Sub gauge
SEL675D
SEL676D
-Water Temp Sensor Check -
Cylinder head R H side
SEL677D
-Oil Pressure Sensor Check -
-
011 filter 7 \
SEL678D
Ohmmeter
terminal With engine With engine
stopped 1 running (idling)
ca On
+I;'''' I More than 74Q I Less than 60.Q
EL-56