1998 NISSAN PATROL Ya go

Wiring Diagram Ð CLOCK Ð
TEL448A
CLOCK
EL-157

System Description
The rear window defogger system is controlled by the smart entrance control unit. The rear window defogger
operates only for approximately 15 minutes.
Power is supplied at all times
+to rear window defogger relay terminalj
3
+through 15A fuse (No.43, located in the fuse and fusible link box) and
+to rear window defogger relay terminalj
6
+through 20A fuse (No.44, located in the fuse and fusible link box).
With the ignition switch in the ON or START position, power is supplied
+to the rear window defogger relay terminalj
1and
+to smart entrance control unit terminalj
12
+through 7.5A fuse [No.8, located in the fuse block (J/B)].
Ground is supplied to terminalj
2of the rear window defogger switch through body grounds.
When the rear window defogger switch is turned ON, ground is supplied
+through terminalj
1of the rear window defogger switch
+to smart entrance control unit terminalj
8.
Terminalj
9of the smart entrance control unit then supplies ground to the rear window defogger relay termi-
nalj
2.
With power and ground supplied, the rear window defogger relay is energized.
Power is supplied
+through terminalsj
5andj7of the rear window defogger relay
+to the rear window defogger.
The rear window defogger has an independent ground.
With power and ground supplied, the rear window defogger ®laments heat and defog the rear window.
When the system is activated, the rear window defogger indicator illuminates in the rear window defogger
switch.
Power is supplied
+to terminalj
3of the rear window defogger switch
+from terminalj
5of the rear window defogger relay.
Terminalj
4of the rear window defogger switch is grounded through body grounds.
REAR WINDOW DEFOGGER
EL-158

Wiring Diagram Ð DEF Ð/LHD Models
TEL449A
REAR WINDOW DEFOGGER
EL-159

TEL450A
REAR WINDOW DEFOGGER
Wiring Diagram Ð DEF Ð/LHD Models (Cont'd)
EL-160

Wiring Diagram Ð DEF Ð/RHD Models
TEL657A
REAR WINDOW DEFOGGER
EL-161

TEL658A
REAR WINDOW DEFOGGER
Wiring Diagram Ð DEF Ð/RHD Models (Cont'd)
EL-162

Trouble Diagnoses
SYMPTOM: Rear window defogger does not activate, or does
not go off after activating.
CHECK REAR WINDOW DEFOGGER
OUTPUT SIGNAL.
1. Turn ignition switch to ON position.
2. Check voltage between control unit har-
ness terminalsj
9and ground.
NG
cOK
Check the following.
+Rear window defogger
relay
(Refer to EL-164.)
+Rear window defogger
circuit
+Rear window defogger
®lament
(Refer to EL-164.)
1. Disconnect control unit connector.
2. Turn ignition switch to ON position.
3. Check voltage between control unit ter-
minalj
9and ground.
Battery voltage should exist.
OK
cNG
Check the following.
+7.5A fuse [No.
8,
located in the fuse block
(J/B)]
+Rear window defogger
relay
+Harness for open or
short between control
unit and fuse
CHECK REAR WINDOW DEFOGGER
SWITCH INPUT SIGNAL.
Check continuity between control unit ter-
minalj
8and ground.
OK
cNG
Check the following.
+Rear window defogger
switch
(Refer to EL-164.)
+Harness for open or
short between control
unit and rear window
defogger switch
+Rear window defogger
switch ground circuit
CHECK IGNITION INPUT SIGNAL.
Check voltage between control unit termi-
nalj
12and ground.
OK
cNG
Check the following.
+7.5A fuse [No.
8located in the fuse block
(J/B)]
+Harness for open or
short between control
unit and fuse
CHECK CONTROL UNIT GROUND CIR-
CUIT.
Check continuity between control unit ter-
minalj
18and ground.
Continuity should exist.
OK
cNG
Repair harness or connec-
tors.
Replace control unit.
Condition Voltage [V]
Rear window defogger
switch is released.Approx. 12
Rear window defogger
switch is pushed.0
Condition of
defogger switchContinuity
Rear window defogger
switch is pushed.Ye s
Rear window defogger
switch is released.No
Condition Voltage [V]
Ignition switch is ``ON''. Approx. 12
Ignition switch is ``OFF''. 0
SEL856UA
SEL857UA
SEL858UA
SEL859UA
SEL854UC
.
.
.
.
.
REAR WINDOW DEFOGGER
EL-163

Electrical Components Inspection
REAR WINDOW DEFOGGER RELAY
Check continuity between terminalsj3andj5,j6andj7.
Condition Continuity
12V direct current supply between
terminalsj
1andj2Ye s
No current supply No
REAR WINDOW DEFOGGER SWITCH
Check continuity between terminals when rear window defogger
switch is pushed and released.
Terminals Condition Continuity
j
1-j2
Rear window defogger
switch is pushedYe s
Rear window defogger
switch is releasedNo
Filament Check
1. Attach probe circuit tester (in volt range) to middle portion of
each ®lament.
+When measuring voltage, wrap tin foil around the top of
the negative probe. Then press the foil against the wire
with your ®nger.
2. To locate burned out point, move probe to left and right along
®lament. Test needle will swing abruptly when probe passes the
point.
+If a ®lament is burned out, circuit tester registers 0 or 12
volts.
SEC202B
SEL430TC
SEL263
SEL122R
SEL266
REAR WINDOW DEFOGGER
EL-164