Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 1375

ELECTRICAL-BODY AND CHASSIS  8-65

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

13 

C-42

 - ground and

15 

C-42

 - 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-9 or 3 

C-26

 fuse No.

EB-8

Open circuit and/or poor

connector contact

NG

OK

Reinstall or replace fuse No.

EB-8 or No. EB-9

Fuse No. EB-8 (10A) or
No. EB-9 (10A) (Relay and
fuse box)
(No. EB-9 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

assembly

Headlight connector continuity

Blown filament

NG

Repair open circuit or

connector contact

Wiring continuity between

headlight and dimmer

⋅passing

switch

Open circuit between

headlight and dimmer

⋅passing

switch

NG

OK

8-66  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-1

- 5 

X-1

  (Should be no

continuity)

Relay point fused

NG

Replay the combination switch

Lighting switch continuity
between connector 1 

C-42

-7 

C-42

 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
14 

C-42

 - 16 

C-42

 when

switch is not operating
(Should be no continuity)

Switch point fused or faulty

NG

Repair short circuit

between 4 

X-1

 - 1 

C-42

and 4 

X-1

 - 14 

C-42

Check if headlight goes out

when connector 

C-42

 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 16 

C-42

 - 

C-2

Poor ground point contact

NG

OK

Clean the light lens

Headlight lens

Lens dirty

NG

OK

ELECTRICAL-BODY AND CHASSIS  8-67

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-1

 - 14 

C-42

Voltage between

14 

C-42

 - 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

switch

Dimmer switch

Loose beam lever or foreign

material in switch

NG

8-68  ELECTRICAL-BODY AND CHASSIS

TAIL LIGHT, LICENSE PLATE LIGHT, CLEARANCE LIGHT AND ILLUMINATION
CONTROLLER

1. All lights do not light

Checkpoint

Trouble Cause

Countermeasure

Repair or replace the

combination switch

Lighting switch continuity

between connector

8 

C-42

 - 7 

C-42

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-12

Fuse No. EB-12 (15A, 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 

T-6

 - 4 

T-6

 (RH)

or 3 

T-1

 - 4 

T-1

 (LH)

Open circuit or poor connector

contact

NG

OK