ISUZU TF SERIES 2004 Workshop Manual

ELECTRICAL-BODY AND CHASSIS 8A-113
CIRCUIT DIAGRAM



RTW48AXF010801

8A-114 ELECTRICAL-BODY AND CHASSIS
LIGHTING
PARTS LOCATION (RHD)







RTW48AXF014501 & RTW48AXF014601

ELECTRICAL-BODY AND CHASSIS 8A-115

PARTS LOCATION (LHD)






RTW48AXF014701 & RTW48AXF014801

8A-116 ELECTRICAL-BODY AND CHASSIS

CIRCUIT DIAGRAM (RHD) G.EXP





RTW48AXF014401

ELECTRICAL-BODY AND CHASSIS 8A-117

CIRCUIT DIAGRAM (RHD) EUROPE



RTW48XF026501

8A-118 ELECTRICAL-BODY AND CHASSIS

CIRCUIT DIAGRAM (LHD) G.EXP




RTW48AXF014201

ELECTRICAL-BODY AND CHASSIS 8A-119

CIRCUIT DIAGRAM (LHD) EUROPE




RTW48AXF014301

8A-120 ELECTRICAL-BODY AND CHASSIS
TROUBLE SHOOTING
HEADLIGHT
1. Both the headlights (high and low beam) do not light

Checkpoint Trouble Cause Countermeasure


Repair the wiring

Poor ground point contact
NG

Repair open circuit or
connector contact


Repair open circuit


Repair or replace the
combination switch


Voltage between 1
B-60 -
ground


Open circuit between lighting
relay and lighting switch

Open circuit between battery
positive terminal and lighting
relay

Combination switch continuity

Poor switch contact or sw
faulty

Voltage between
5
X-12 - ground and
2
X-12 - ground


Reinstall or replace the
lighting relay

Lighting relay

Poor relay contact or relay
faulty

NG NG NG NG OK
OK
OK OK

Ground point contact (C-36)


Repair open circuit
Wiring continuity between

B-60 - C-36


Open circuit
NG OK

ELECTRICAL-BODY AND CHASSIS 8A-121
2. High or low beam does not light on both headlights

Checkpoint Trouble Cause Countermeasure


Repair or replace the
combination switch

Dimmer
passing switch
continuity

Poor switch contact or switch
faulty
NG

Repair open circuit or
connector contact
Voltage between
4
X-4 - ground and
4
B-60 - ground

Open circuit between
headlight and dimmer
passing
switch
NG OK



3. RH (or LH) high and low beam does not light



Replace the headlight bulb

Headlight connector continuity

Blown filament or air leakage
NG

Repair or replace the wire
and/or connector
Wiring continuity between
connector 3
C-19 - fuse No.
EB-7 or 3
C-26 fuse No.
EB-8

Open circuit and/or poor
connector contact
NG OK

Reinstall or replace fuse No.
EB-7 or No. EB-8
Fuse No. EB-7 (10A) or
No. EB-8 (10A) (Relay and
fuse box)
(No. EB-7 RH, No. EB-8: LH)
Poor installation or blown fuse
NG
OK



4. High or low beam does not light on one headlight (RH or LH)

Replace the headlight
assemblyHeadlight connector continuityBlown filament NG
Repair open circuit or
connector contactWiring continuity between
headlight and dimmer
passing
switchOpen circuit between
headlight and dimmer
passing
switch NG OK

8A-122 ELECTRICAL-BODY AND CHASSIS
5. Headlight does not go out

Checkpoint Trouble Cause Countermeasure


Replace the lighting relay
Lighting relay continuity
between connector 1
X-12
- 2
X-12 (Should be no
continuity)

Relay point fused
NG

Replay the combination switch
Lighting switch continuity
between connector 3
B-60
-1
B-60 when switch is
OFF(Should be no continuity)

point fused or faulty

NG
OK OK

Repair or replace the
combination switch
Dimmer
passing switch con-
tinuity between connector
3
B-60 - 1 B-60 when switch
is not operating
(Should be no continuity)

Switch point fused or faulty
NG
Repair short circuit
between 4
X-12 - 3 B-60
and 4
X-1 - 2 B-60
Check if headlight goes out
when connector
C-30 is
disconnected


Short circuit
NG OK



6. Insufficient headlight brightness



Replace the headlight bulb

Headlight bulb

Bulb filament faulty
NG

Repair the wiring
Dimmer
passing switch
Wire continuity between con-
nector 1
B-60 - C-36


Poor ground point contact
NG OK

Clean the light lens

Headlight lens

Lens dirty
NG
OK