Isuzu Trooper (1998-2002 year). Service manual - part 900

8D–134

WIRING SYSTEM

Check point

Trouble mode

Fuse

F–8

(15A or 20A)

Cable

harness

Fog light

bulb

3–1. Both FRT fog lights
        inoperative
(while the clearance light is ON)

3–2. FRT fog light on the left 
      (or rigth) side inoperative
(while the clearance light is ON)

LH

RH

FRT

fog light

SW

FRT

fog  light

relay

RR

fog light

SW

RR

fog light

relay

3.  FRT fog lights

WIRING SYSTEM

8D–135

1-1.   Both Headlights Inoperative

•

IS THE LIGHTING RELAY NORMAL?

YES

•

IS   B-19    GROUNDED SECURELY?

YES

REPLACE THE LIGTHING RELAY

NO

•

DISCONNECT THE LIGTHING SW CONNECTOR

•

IS THE BATTERY VOLTAGE APPLIED BETWEEN THE HARNESS
SIDE CONNECTOR 1    B-12    AND GROUND?

YES

GROUND IT SECURELY

NO

•

REMOVE THE LIGHTING SW

•

IS THERE CONTINUITY BETWEEN 1   B-12    AND 7   B-12    WHEN 
SETTING THE LIGHTING SW AT THE   HEADLIGHT POSITION ?

REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN THE FUSUBLE LINK
FL-1 (80A) AND 1    B-12

NO

YES

REPAIR OR REPLACE THE LIGHTING SW

NO

REPAIR  A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN THE HARNESS SIDE CONNECTOR 
7    B-12   AND     B-19    

•

IS THE DIODE NORMAL?

REPLACE THE DIODE

NO

YES

8D–136

WIRING SYSTEM

1-2.   Headlight On The Left (Or Right) Side Inoperative

1-3.   Both Headlights In Low-Beam Inoperative

YES

•

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

YES

REPLACE THE FUSE

NO

•

IS THE FUSE F-4 (15A) (OR F-5 (15A)) NORMAL?

REPAIR A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN 
FUSE F-4 (15A) AND 3   C-21   (LH)
FUSE F-5 (15A) AND 3   C-32   (RH)

REPLACE THE BULB

NO

•

YES

REPAIR A POOR CONNECTION AT THE CONNECTORS OR
AN OPEN CIRCUIT BETWEEN
13   B-12    AND 10   H-15

REPAIR OR REPLACE THE DIMMER•PASSING SW

NO

•

WITH THE SWITCH AT THE LOW-BEAM POSITION, IS
THERE CONTINUITY BETWEEN THE SW CONNECTOR
TERMINALS 13    B-12   AND 16   B-12

DISCONNECT THE DIMMER•PASSING SW CONNECTOR
(COMBINATION SW)

WIRING SYSTEM

8D–137

1–4.   Headlight Low-Beam On The Left (Or Right) Side Inoperative

•

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

YES

•

IS THE FUSE F–4 (15A) (OR F–5 (15A))
NORMAL?

YES

REPLACE THE BULB

NO

•

DISCONNECT THE DIMMER·PASSING SW CONNECTOR

•

WITH THE SWITCH AT THE LOW–BEAM POSITION, IS THERE 
CONTINUITY BETWEEN 13   B–12   AND 16   B–12   ?

YES

REPLACE THE FUSE

NO

REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN 3   C–21   AND F–4 
(15A) (OR 3   C–32    AND F–5 (15A))

NO

REPAIR OR REPLACE THE DIMMER·PASSING SW

REPAIR  A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN 13   B–12   AND 1   C–21   (OR 13   B–12
AND 1   C–32   )

•

IS THE CONTINUITY BETWEEN
3    C–21   AND F–4 (15A) (OR 3   C–32  
AND F–5 (15A)) NORMAL?

NO

YES