switch ISUZU TF SERIES 2004 Workshop Manual

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

ELECTRICAL-BODY AND CHASSIS 8A-123
7. Passing light does not function when dimmer switch is operated

Checkpoint Trouble Cause Countermeasure


Repair or replace the dimmer
switch

Dimmer switch

Poor switch point contact
NG

Repair open circuit between
4
X-12 - 3 B-60

Voltage between
3
B-60 - ground (Should
be battery voltage present)


Open circuit
NG OK



8. Headlight beam does not change when dimmer switch is operated

Repair or replace the dimmer
switchDimmer switchLoose beam lever or foreign
material in switch NG

8A-124 ELECTRICAL-BODY AND CHASSIS
TAIL LIGHT, LICENSE PLATE LIGHT, CLEARANCE LIGHT

1. All lights do not light

Checkpoint Trouble Cause Countermeasure



Repair or replace the
combination switch
Lighting switch continuity
between connector
2
B-60 - 1 B-60


Poor switch point or connector
contact
NG

Reinstall or replace the tail
relay

Tail relay


Poor relay contact or relay
faulty
NG OK

Reinstall or replace the fuse
No. EB-6

Fuse No. EB-6 (10A, Relay
and fuse box)

Poor fuse contact or blown
NG
OK



2. Tail light does not light


Replace the bulb or repair
connector contact

Tail light bulb continuity

Bulb burned out or poor
connector contact
NG

Repair open circuit or
connector contact
Continuity between connector
3
F-5 - 4 F-5 (RH)
or 3
F-6 - 4 F-6 (LH)


Open circuit or poor connector
contact
NG OK

ELECTRICAL-BODY AND CHASSIS 8A-125
TAIL LIGHT-LH, LICENSE PLATE LIGHT, CLEARANCE LIGHT

1. All lights do not light (EC-LHD)

Checkpoint Trouble Cause Countermeasure



Repair or replace the
combination switch
Lighting switch continuity
between connector
2
B-60 - 1 B-60


Poor switch point or connector
contact
NG

Reinstall or replace the tail
relay

Tail relay


Poor relay contact or relay
faulty
NG OK

Reinstall or replace the fuse
No. EB-6

Fuse No. EB-6 (10A, Relay
and fuse box)

Poor fuse contact or blown
NG
OK



2. Tail light does not light


Replace the bulb or repair
connector contact

Tail light bulb continuity

Bulb burned out or poor
connector contact
NG

Repair open circuit or
connector contact

Continuity between connector
or 3
F-6 - 4 F-6 (LH)

Open circuit or poor connector
contact
NG OK

8A-126 ELECTRICAL-BODY AND CHASSIS
TAIL LIGHT-RH

1. All lights do not light (EC-LHD)

Checkpoint Trouble Cause Countermeasure



Repair or replace the
combination switch
Lighting switch continuity
between connector
2
B-60 - 1 B-60


Poor switch point or connector
contact
NG

Reinstall or replace the tail
relay

Tail relay


Poor relay contact or relay
faulty
NG OK

Reinstall or replace the fuse
No. EB-6

Fuse No. EB-5 (10A, Relay
and fuse box)

Poor fuse contact or blown
NG
OK



2. Tail light does not light


Replace the bulb or repair
connector contact

Tail light bulb continuity

Bulb burned out or poor
connector contact
NG

Repair open circuit or
connector contact

Continuity between connector
3
F-5 - 4 F-5 (RH)


Open circuit or poor connector
contact
NG OK

ELECTRICAL-BODY AND CHASSIS 8A-129
Installation
Follow the removal procedure in the reverse order to install the
headlight.
Pay close attention to the important points mentioned in the
following paragraphs.


Connector
Be absolutely sure that the headlight connector is securely
connected.
This will prevent a contact and an open circuit.

This illustration is based on RHD model

LIGHTING SWITCH
Removal
1. Disconnect the battery ground cable.
2. Remove the steering wheel
1.
Refer to the “STEERING” Section of this manual.
3. Remove the Instrument panel lower cover
2.
4. Remove the steering column cover
3.


This illustration is based on RHD model
5. Disconnect the connector.
6. Remove the lighting switch from the steering shaft.





Installation
Follow the removal procedure in the reverse order to install the
lighting switch.
Pay close attention to the important points mentioned in the
following paragraphs.



Connector
Be absolutely sure that the lighting switch connector is securely
connected.
This will prevent a poor contact and an open circuit.


Wire Harness
Do not pinch the wire harnesses between the cluster and the
meter hood during the cluster installation procedure.
Wire damage will result.

ELECTRICAL-BODY AND CHASSIS 8A-131


LICENSE PLATE LIGHT
Removal
1. Remove the lens cover 1 and the connector 2.
2. Pull the bulb
3 to remove it.



Installation
Follow the removal procedure in the reverse order to install the
license plate light.
Pay close attention to the important points mentioned in the
following paragraphs.



Bulb
Be absolutely sure that the license plate light bulb is correctly
installed.
This will prevent a poor contact and open circuit.



HEADLIGHT BEAM SWITCH
(COMBINATION SWITCH)
Removal
1. Disconnect the battery ground cable.
2. Remove the screws on the lower part of the steering wheel.
3. Remove the horn pad.
4. Remove the wiring connector.
5. Remove the steering wheel fixing nuts.
6. Remove the steering wheel.
Refer to the "STEERING" Section of this manual.
7. Remove the Instrument panel lower cover.
8. Remove the steering column cover.
9. Disconnect the connector.
10. Remove the headlight beam switch (lever) from the steering
shaft (combination switch).


Installation
Follow the removal procedure in the reverse order to install the
headlight beam switch (lever).
Pay close attention to the important points mentioned in the
following paragraphs.



Connector
Be absolutely sure that the headlight beam switch connector is
securely connected.
This will prevent a poor contact and an open circuit.

8A-134 ELECTRICAL-BODY AND CHASSIS
INSPECTION AND REPAIR





Switch side Harness side
B-60 B-60



LIGHTING SWITCH
Lighting Switch Connections

Terminal
SW No.
position 3 2 1
OFF
Tail

Headlight





Switch side Harness side
B-60 B-60


HEADLIGHT BEAM SWITCH
Headlight Beam and Passing Switch
Connections
Terminal NO.
SW position 1 4
HI
At “Dimmer” position
LO
At “Passing” Position