Isuzu N-Series. Service manual - part 1062

CAB AND CHASSIS ELECTRICAL 8-353

Vacuum Switching Valve: Transfer Control (for
4WD)

Inspection
Connect the vacuum switching valve connector terminal
No. 2 to the battery (+) terminal and terminal No. 4 to the
(

−) terminal and then check the continuity among each

port.

4WD Detective Switch

Inspection of the 4WD Warning Light Circuit

1. Disconnect the 4WD switch connectors.
2. Connect the harness side connector terminals.
3. Check to see if the indicator light comes on with the

starter switch “ON”.
Check the bulb or harness when the result of in-
spection is found abnormal.

Inspection

1. Shift the transfer lever to the 4H (4L) position.
2. Check to see if there is continuity between the

4WD switch connectors.
Replace the switch when the result of the inspec-
tion is found abnormal.

N8A5446E

N8A5447E

N8A5448E

8-354 CAB AND CHASSIS ELECTRICAL

ABS (Anti-lock Brake System, Without ASR)

Parts Location

H-16

J-74 F/RH SENSOR

B-66 ST

OPLIGHT SW

(BRAKE SW)

B-1 EARTH ;

FRAME (FR)

B-67 IGNITION SW "A"

B-233,B-234 ECM

FUSE BOX ASM

F-2,F-5,F-16 

STARTER SW

J-148 R/RH

SENSOR (24V)

J-177

ABS EHCU

B-52 EXH. BRAKE

IND. LAMP (METER) 

B-51

ABS ARNING LIGHT

(METER) 

J-75 F/LH SENSOR

B-79 DATA LINK CONNECTOR

J-9 EAR

TH ;

 FRAME

(12V)

(24V)

X-5 ABS INDICATOR RELAY

X-8 EXHAUST BRAKE RELAY

 (24V)

RELAY BOX ASM (No.1)

X-25 EXHAUST BRAKE CONTROL RELAY

X-28 EXHAUST BRAKE CUT RELAY

J-23 DIODE

FL-1,FL-2,FL-9 FUSIBLE LINK

J-31 EXH. BRAKE

MAGNETIC VALVE

B-75

ACCEL SW

H-13

P-5

P-1

~

P-4

BATTERY    

H-17

H-14

H-15

J-149 R/LH

SENSOR (24V)

R-6

STOPLIGHT (RH)

R-1

STOPLIGHT (LH)

SENSOR (12V)

J-78 R/RH,R/LH

B-7 EARTH ;

HEADLIGHT B/T

B-69

EXH. BRAKE SW

B-89 CLUTCH SW

H-5

~

H-8

N8A0537E

CAB AND CHASSIS ELECTRICAL 8-355

Circuit Diagram

For 12 Volt (4JH1 Engine)

ABS

60A

P-5

P-2

BATTERY

P-1

B-1

B-7

0.85B

H-6

2

B-51

7

B-51

8

FL-9

MAIN
100A

FL-1

KEY SW

50A

FL-2

METER

10A

F-16

8B

8W/B

3R

8W/B

3W/B

3W/B

0.5G/Y

0.5G

SW ; STOP LIGHT

B

OFF

ACC

ON

ST

B-67

2

B-67

3

KEY SW

3W/L

0.5B

2B

3B

0.5B/Y

0.5B/Y

0.5B/Y

STOP LIGHT

10A

F-5

B-66

4

B-66

1

0.5B/Y

0.5W

X-5

4

X-5

5

X-5

1

X-5

3

3B/Y

METER

ABS

RELAY ;
ABS IND.

3W/L

H-7

1

3B

3B

2B

0.3W/V

22

H-5

J-9

P-4

P-3

FRAME-LH (CENTER)

FRAME LH (FRONT)

HEADLIGHT BRACKET (LH)

C

D

E

F

A

B

G

H

N8A5590E

8-356 CAB AND CHASSIS ELECTRICAL

J-78

4

J-78

3

0.5R

0.5W

0.3W/G

0.3W/B

0.3W/G

0.3W/B

0.3W/B

0.5B

0.5B

SPEED
SENSOR
(RR,RH)

J-74

1

J-74

2

0.5P

0.5L

SPEED
SENSOR
(FRT,RH)

J-75

1

J-75

2

0.5V

0.5R/B

0.5P

0.5L

0.5V

0.5R/B

SPEED
SENSOR
(FRT,LH)

0.85B

J-177

22

J-177

16

STOP LAMP

EHCU ; ABS

ECM

B-234  (62)

RL 12V

34

J-78

2

J-78

1

24

MOTOR +B

RL SIG

32

2

VALVE +B

FL SIG

33

23

MOTOR GND

FL GRD

10

1

VALVE GND

FR SIG

11

8

EXH.B/CUT
OUT

FR GRD

21

7

EXH.B/CUT
IN

RR 12V

12

6

IND.

RR SIG

29

IG

MODE1

MODE2

MODE3

J1850

4

FRASH

VEHICLE TYPE CONNECTOR

NKR77-3 (FLAT LOW)

EXCEPT NKR77-3
(EXCEPT FLAT LOW)

2B

3R

3R

3B

3B

0.5B/Y

0.3W/V

0.3W/V

0.3W/V

0.5B/Y

0.5B/Y

0.5B/G

0.5B/R

0.5B/W

1.25B

0.5G

0.5G

0.5G

0.5G

0.5G

H-5

11

2

(30)

ECM

H-16

2

STOP

LIGHT

(RH)

STOP

LIGHT

(LH)

0.5G

1.25B

1.25B

0.5L

0.5Y

SPEED
SENSOR
(RR,LH)

16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

H-5

35

H-5

36

H-5

40

H-14

10

H-14

11

H-14

12

DATA LINK
CONNECTOR

B-79

0.3W/G

H-5

27

H-5

26

3R

0.5G

0.5LG/B

0.5LG/W

0.5LG/B

0.5LG

0.5LG/W

0.5LG/B

3B

3B

ECM

B-234  (32)

B-234

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

J-177

H-14

H-14

15

H-14

16

H-15

1

H-15

2

H-15

5

H-15

6

H-15

4

H-15

3

H-15

7

H-15

8

3

J-177

17

J-177

14

J-177

15

J-177

H-14

9

H-17

4

H-17

3

H-17

1

H-17

2

H-17

H-17

H-17

H-17

H-17

H-17

H-17

H-17

R-1

2

6

R-1

7

H-16

7

H-14

R-6

2

6

R-6

C

D

A

B

E

F

G

H

0.5Y

0.5L

ECM

35

45

B-234

B-234

N8A5591E