Isuzu N-Series. Manual - part 1014

CAB AND CHASSIS ELECTRICAL 8-161

Circuit Diagram

For 12 Volt

P-1

P-2

FL-1

100A(12V)

MAIN

B

ST

ACC

ON

STARTER SW

B-67

1

H-7

P-5

FRAME

FL-2

50A(12V)

KEY SW

3W/L

3W/L

3W/B

2

3

B-67

F-12

10A

H/LAMP LEVEL

0.5R/W

2L

P-3

P-4

4JH1

RELAY; KEY ON

3L

0.5B

3B/Y

3B/Y

X-1

X-1

X-1

X-1

ACG B

2L

FUSE BLOCK

2

B-421

3

B-421

4

B-421

5

B-421

6

0.5O/G

0.5O/B

0.5O/W

0.5O/L

0.5O

B-421

1

B-421

14

B-421

4

B-156

10

B-156

6

B-156

7

3

2

4

0

1

B-156

8

B-156

9

B-156

R5

R6

RESISTOR;

H/L LEVELING

R4

R3

R2

R1

0.5R/W

0.5R/W

0.5B

1

B-155

3

B-155

2

0.5B

0.5B

B-155

ACTUATOR; HLL (LH)

(DR SIDE HEAD LAMP)

1

B-152

3

B-152

2

B-152

ACTUATOR; HLL (RH)

(AS SIDE HEAD LAMP)

0.5R/W

0.5R/Y

0.5R/Y

SW; H/L LEVELING

1

3

2

5

N8A0148E

8-162 CAB AND CHASSIS ELECTRICAL

For 24 Volt

P-1

P-2

FL-1

100A or 120A

MAIN

B

ST

ACC

ON

STARTER SW

B-67

1

H-7

FL-2

40A

KEY SW

3W/L

3W/L

3W/B

5W/B

3W/B

2

3

B-67

F-12

10A

H/LAMP LEVEL

2L

RELAY; KEY ON

3L

0.5B

3B/Y

3B/Y

X-11

X-11

X-11

X-11

ACG B

FUSE BLOCK

P-3

P-4

P-5

FRAME

2

B-421

3

B-421

4

B-421

5

B-421

6

0.5O/G

0.5O/B

0.5O/W

0.5O/L

0.5O

B-421

1

B-421

14

B-421

1

B-420

6

B-420

3

B-420

2

B-420

4

B-156

10

B-156

6

B-156

7

3

2

4

0

1

B-156

8

B-156

9

B-156

R5

R6

RESISTOR;

H/L LEVELING

R4

R3

R2

R1

0.5R/W

0.5B/W

1

B-155

3

B-155

2

B-155

ACTUATOR; HLL (LH)

(DR SIDE HEAD LAMP)

1

B-152

3

B-152

2

B-152

ACTUATOR; HLL (RH)

(AS SIDE HEAD LAMP)

0.5R/W

0.5B/W

0.5R/Y

0.5R/Y

SW; H/L LEVELING

CONVERTER;

DC-DC(HLL)

0.5L/O

0.5R/W

0.5B/W

1

3

2

5

N8A0388E

CAB AND CHASSIS ELECTRICAL 8-163

Connector List

H-7

No.

Connector Face

B-7

B-67

B-67

B-152

B-155

B-156

P-1

P-2

000-012

004-001

1

2

3

4

004-002

2
4

1
3

003-016

3

1

2

003-016

3

1

2

010-002

5

2

1

6

7

8

9

4

3

10

000-004

000-003

P-5

B-420

(24 V)

B-421

X-1

(12V)

X-11

(24 V)

No.

Connector Face

000-007

006-019

4

5

6

1

2

3

014-002

1 2 3

7 8 9 10

11

4

12

5

13

6

14

005-006

005-001

1

3

2

4

5

1

2

1

2

1 2 3 4

5 6 7 8

9 10 11 12 13

14 15 16 17 18

2

1

2

1

4 3 2 1

8 7 6 5

13 12 11 10 9

18 17 16 15 14

H - 6

H - 7

H - 8

N8A5489E

8-164 CAB AND CHASSIS ELECTRICAL

Diagnosis

Quick Chart for Check Points

1. Both Actuators Inoperative

Check point

Fuse

F-12 (10 A)

Headlight 

leveling 

switch

Headlight 

leveling 

actuator

Cable 

harness

Trouble 
mode

1. Both actuators inoperative

❍

❍

❍

2. Actuator on the left (right) side inop-
erative

❍

❍

3. When leveling SW is turned to a 
certain position, actuator inoperative

❍

❍

❍

• IS FUSE  F-12  (10A) NORMAL?

• IS  B-7  GROUNDED SECURELY?

YES

NO

REPLACE THE FUSE

• TURN THE STARTER SW TO ON POSITION

• IS THE BATTERY VOLTAGE APPLIED BETWEEN THE

FUSE TERMINAL AND THE GROUND?

YES

NO

GROUND IT SECURELY

• IS THE CONTINUITY IN THE HEADLIGHT LEVELING 

SW NORMAL?

YES

NO

REPAIR AN OPEN CIRCUIT BETWEEN STARTER
SW AND FUSE  F-12  (10A)

• IS THERE CONTINUITY BETWEEN 6 B-156  AND THE

GROUND?

YES

NO

REPAIR OR REPLACE THE SWITCH

REPAIR A POOR CONNECTION AT THE CONNECTORS 
OR AN OPEN CIRCUIT BETWEEN FUSE  F-20  AND 
1 B-155  (1 B-152  )

YES

NO

REPAIR AN OPEN CIRCUIT BETWEEN
6 B-156  AND  B-7  

N8A0149E