Lexus SC300 / Lexus SC400. Manual - part 161

26

CD player

WOOFER DOES NOT WORK

HINT: The part names and terminals indicated in brackets ( ) are for models with a Nakamichi system.

Is radio operating normally?

Is there battery voltage between the following ter-
minals with connector connected?

 Woofer amplifier 3 (Power amplifier C3) – ground

 Woofer amplifier 4 (Power amplifier C4) – ground

Woofer faulty

Radio receiver assembly faulty.

Wire harness faulty.

Wire harness faulty.

Wire harness faulty.

Wire harness faulty.

Wire harness faulty.

Is there battery voltage between the following ter-
minals with connector connected?

 Woofer amplifier 6 (Power amplifier C6) – ground

Is there continuity between the following terminals
with connector disconnected?

 Woofer amplifier 7 (Power amplifier C7) – ground

Is there continuity between the following terminals
with connector disconnected?

 Woofer amplifier 9 (Power amplifier C9) –

  Woofer speaker 2

 Woofer amplifier 10 (Power amplifier C10) –

  Woofer speaker 1

Is there continuity between the following terminals
with connector disconnected?

 Woofer amplifier 9 (Power amplifier C9) – ground

 Woofer amplifier10 (Power amplifier C10) – ground

Temporarily install another woofer.
Functions OK?

Radio receiver assembly faulty.

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

BE–255

27

CD player

WOOFER VOLUME FAINT

HINT: The part names and terminals indicated in brackets ( ) are for models with a Nakamichi system.

Is radio operating normally?

Is there continuity between the following terminals
with connector disconnected?

 Radio receiver assembly D1 – Woofer amplifier 1

   (Power amplifier 1 (Power amplifier C1)

 Radio receiver assembly D5 – Woofer amplifier 1

   (Power amplifier 5 (Power amplifier C5)

Radio receiver assembly faulty.

Wire harness faulty.

Wire harness faulty.

Woofer amplifier faulty.

Radio receiver assembly faulty.

Temporarily install another woofer amplifier.
Functions OK?

Is there continuity between the following terminals
with connector disconnected?

 Radio receiver assembly D1 – ground

 Radio receiver assembly D5 – ground

BE–256

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

28

CD player

SOUND QUALITY POOR

Is radio operating normally?

Is speaker properly installed?

Temporarily install another speaker
Functions OK?

Temporarily install another CD auto changer.
Functions OK?

Temporarily install another power amplifier.
Functions OK?

Radio receiver assembly faulty.

Speaker faulty.

Speaker installation faulty

Power amplifier faulty.

Radio receiver assem-
bly faulty

CD changer faulty.

29

CD player

VOLUME REMAINS AT MAXIMUM LEVEL

Is radio operating normally?

Radio receiver assembly faulty.

Wire harness faulty.

Is there continuity between the following terminals
with connector disconnected?

 Radio receiver assembly B1 – Power switch 14

 Radio receiver assembly B3 – Power switch 11

Power switch faulty.

Radio receiver assembly faulty.

When the volume switch is turned from minimum to
maximum, does resistance between terminal 11–14
of power switch changes from 0 to 50 k



?

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

BE–257

30

Noise

NOISE PRODUCED BY VIBRATION OR SHOCK
WHILE DRIVING

Is radio properly installed?

Is radio receiver assembly properly installed?

*1 Is radio power amplifier properly installed?

*2 Is woofer amplifier properly installed?

*1 Is CD auto changer properly installed?

With vehicle stopped, lightly tap each part.
Is noise produced?

Speaker installation faulty.

Radio receiver assembly installation faulty.

Power amplifier installation faulty.

Woofer amplifier installation faulty.

CD auto changer installation faulty.

Each part faulty.

Noise produced by static electricity is accululating in the vehicle body.

BE–258

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM