Lexus SC300 / Lexus SC400. Manual - part 205

2. INSPECT RELAY CIRCUIT

Remove the relay from the junction block and inspect the
connector on junction block side as shown.

Relay

Check for

Tester connection

Condition

Specified value

TAIL

Voltage

(1)–Ground

Constant

Battery voltage

(4)–Ground

P/W MAIN

(6)–Ground

If the circuit is not as specified, refer to 

BE–15

 wiring diagram

and inspect the circuits connected to other parts.

INSPECTION OF RELAY BLOCK NO. 2

1. 

INSPECT FUSE CIRCUIT
Remove the fuse from the relay block and inspect the con-
nector on relay block side as shown.

Fuse

Check for

Tester Connection

Condition

Specified value

ABS NO. 1

Voltage

2–Ground

Constant

Battery voltage

AM1

4–Ground

ALT

5–Ground

MAIN

7–Ground

AM2

9–Ground

ABS NO. 2

11–Ground

INT

13–Ground

–

BODY ELECTRICAL SYSTEM

Power Source

BE–21

Fuse

Check for

Tester Connection

Condition

Specified value

HTR

Voltage

(15)–Ground

Constant

Battery voltage

DEF

(17)–Ground

DOME

(24)–Ground

EFI

(26)–Ground

HAZ–HORN

(28)–Ground

RADIO NO. 1

(30)–Ground

TEL

(32)–Ground

ALT–S

(34)–Ground

TRAC

(36)–Ground

HEAD (RH–LWR)

(38)–Ground

Light control switch turned to TAIL or

HEAD (LH–LWR)

(40)–Ground

HEAD and *ENGINE running

HEAD (RH–UPR)

(44)–Ground

Light control switch turned to HEAD and

HEAD (LH–UPR)

(46)–Ground

dimmer switch turned to HI or FLASH

If the circuit is not as specified, refer to 

BE–15

 wiring diagram

and inspect the circuits connected to other parts.

2. INSPECT 

RELAY 

CIRCUIT

Remove the relay from the relay block and inspect the con-
nector on relay block side as shown.

Relay

Check for

Tester connection

Condition

Specified value

EFI

Voltage

(4)–Ground

Constant

Battery voltage

ST

(10)–Ground

(11)–Ground

DIM

(15)–Ground

Light control switch turned to TAIL or HEAD

(16)–Ground

and *Engine running

IG2

(18)–Ground

Constant

HTR

(24)–Ground

(25)–Ground

H–LP

(28)–Ground

(30)–Ground

DEF

(34)–Ground

(35)–Ground

If the circuit is not as specified, refer to 

BE–15

 wiring diagram

and inspect circuits connected to other parts.

BE–22

–

BODY ELECTRICAL SYSTEM

Power Source

INSPECTION OF RELAY BLOCK NO. 4
AND NO. 5 RELAY BLOCK

1. 

INSPECT FUSE CIRCUIT
Remove the fuse from the relay block and inspect the con-
nector on relay block side as shown.

Fuse

Check for

Tester connection

Condition

Specified value

STHTR

Voltage

2–Ground

Ignition Switch Turn to ON

Battery voltage

If the circuit is not as specified, refer to 

BE–15

 wiring diagram

and inspect the circuits connected to other parts.

2. INSPECT 

RELAY 

CIRCUIT

Remove the relay from the relay block and inspect the con-
nector on junction block side as shown.

Relay

Check for

Tester connection

Condition

Specified value

HORN

Voltage

(8)–Ground

Constant

Battery voltage

IG MAIN

(9)–Ground

(13)–Ground

Continuity

CRNRNG LP

(14)–Ground

Ignition Switch Turned to ON

Battery voltage

(15)–Ground

–

BODY ELECTRICAL SYSTEM

Power Source

BE–23

If the circuit is not as specified, refer to 

BE–15

 wiring diagram

and inspect the circuits connected to other parts.

INSPECTION OF RELAY BLOCK NO. 6
(ABS and TRAC Relay Block)

INSPECT RELAY CIRCUIT

Remove the relay from the relay block and inspect the con-
nector on junction block side as shown.

Relay

Check for

Tester connection

Condition

Specified value

TRAC SOL

Voltage

(1)–Ground

Constant

Battery voltage

TRAC MTR

(7)–Ground

ABS SOL

(11)–Ground

ABS MIR

(17)–Ground

If the circuit is not as specified, refer to 

BE–15

 wiring diagram

and inspect circuits connected to other parts.

BE–24

–

BODY ELECTRICAL SYSTEM

Power Source