Isuzu Trooper (1998-2002 year). Manual - part 909

8D–170

WIRING SYSTEM

Diagnosis

Quick Chart for Check Point

1.  RHD

2.  LHD

Trouble
mode

Check point

RHD-1

RHD-2

RHD-2

Fuse

F-12

(15A)

Lighting

SW

Tail

relay

Clearance

light bulb

License 

plate light

bulb

Cable harness

1-3  Taillight on the left (or
        right) side inoperative

1-4  Both clearance
       lights inoperative

1-5  Clearance light on the left 
       (or right) side inoperative

1-6  License 

plate light

       inoperative

1-7  License plate 

light on the 

       left (or right)

side inoperative

1-1  All illumination lights
       inoperative

1-2  Both Taillights inopera-
       tive

Taillight 

bulb

Trouble Mode

Check point

Fuse

F-12

(10A)

Lighting

SW

Taillight

bulb

Clearance

light bulb

License

plate light

bulb

Cable

harness

2-1 All illumination lights

inoperative

2-2 Both taillights

inoperative

2-3 Taillight on the left (or

right) side inoperative

2-4 Both clearance lights

inoperative

2-5 Clearance light on the left 

(or right) side inoperative

2-6

LHD-1

LHD-2

LHD-2

License plate 
light 
inoperative

2-7 License plate 

light on the left 
(or right) side
inoperative

Fuse

F-11

(10A)

Tail

relay

2-8 Both taillight and 

clearance light on the left 
(or right) side inoperative

WIRING SYSTEM

8D–171

1-1  All Illuminations Lights Inoperative

1-2  Both Taillights Inoperative

IS THE BATTERY VOLTAGE APPLIED BETWEEN
HARNESS SIDE CONNECTOR 8  B-12   AND GROUND
WHEN LIGHTING SWITCH IS "ON" ?

REPAIRA POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN 7  B-12   AND  B-19
OR BETWEEN 4  X-9  AND 1  H-41  )

IS FUSE F-12 (15A) NORMAL?

REPLACE THE FUSE

NO

REPAIR OR REPLACE THE SWITCH

NO

IS THE CONTINUITY IN THE LIGHTING SWITCH NORMAL?

YES

YES

REPAIR A POOR CONNECTION AT THE
CONNECTORS OR AN OPEN CIRCUIT
BETWEEN 8  B-12  AND FUSE F-12 (15A)

NO

YES

•

•

•

NO

IS TAIL RELAY (X-9) NORMAL?

YES

•

REPAIR OR REPLACE THE RELAY

•

DOES THE LICENSE PLATE LIGHT LIGHT UP WHEN THE
LIGHTING SWITCH IS AT THE CLEARANCE LIGHT 
POSITION?

YES

NO

GROUND     R-4     SECURELY

REPAIR A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN 4    H-15    AND 10    H-32

8D–172

WIRING SYSTEM

1-3  Taillight On The Left (Or Right) Side Inoperative

IS THE TAILLIGHT BULB ON THE LEFT (OR RIGHT)
SIDE NORMAL?

•

•

YES

NO

REPLACE THE BULB

WITH THE LIGHTING SWITCH AT THE CLEARANCE
LIGHT POSITION, IS THE BATTERY VOLTAGE APPLIED
BETWEEN 6  R-13  (OR 6  R-12 ) AND THE GROUND,
OR 4  F-7  (OR 4  F-8  ) AND THE GROUND?

YES

NO

REPAIR A POOR CONNECTION AT 
THE CONNECTORS OR AN OPEN
CIRCUIT BETWEEN 10  H-32  AND
6  R-13  (OR 9  H-32  AND 6  R-12  ),
OR 10  H-32  AND 4  F-7  (OR 9  H-32
AND 4  F-8  )

REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN 1  R-13  (OR 1  R-12  )
AND  R-4  , OR 2   F-7   (OR 2   F-8  ) AND  R-4

WIRING SYSTEM

8D–173

1-4  Both Clearance Lights Inoperative

IS FUSE F-12 (15A) NORMAL?

•

•

YES

NO

REPLACE THE FUSE

REPLACE THE RELAY

REMOVE THE CONNECTOR OF THE LIGHTING SWITCH

•

IS THERE ANY CONTINUITY BETWEEN 8  B-12  AND
7  B-12  WHEN THE SWITCH IS TURNED TO THE CLEARANCE
LIGHT OR HEADLIGHT POSITION?

YES

NO

GROUND IT SECURELY

YES

NO

YES

NO

YES

NO

REPAIR A POOR CONNECTION AT THE CONNECTORS OR
AN OPEN CIRCUIT BETWEEN 4  X-9  AND 1  H-41

•

IS THE BATTERY VOLTAGE APPLIED BETWEEN THE
HARNESS SIDE CONNECTOR 8  B-12  AND THE GROUND?

REPAIR OR REPLACE THE LIGHTING
SWITCH

REPAIR A POOR CONNECTION AT 
THE CONNECTORS OR AN OPEN
CIRCUIT BETWEEN 3  X-9  AND 
8  B-12

•

IS THE TAIL RELAY NORMAL?

IS 1  C-16   GROUNDED SECURELY?

•