Lexus SC300 / Lexus SC400. Manual — part 155

7

Radio

WOOFER VOLUME FAINT

A. without CD player type

Wire harness faulty.

Wire harness faulty.

Radio receiver assembly faulty.

Is tape player operating normally?

Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly D1–ground

Radio receiver assembly D5–ground

Woofer amplifier faulty.

Is there continuity between the following terminals
with connector disconnected?

Radio receiver amplifier D1 – Woofer amplifier 1

Radio receiver amplifier D5 – Woofer amplifier 5

Radio receiver assembly faulty.

Temporarily install another woofer amplifier.
Functions OK?

B. with CD player type

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

Wire harness faulty.

Wire harness faulty.

Radio receiver assembly faulty.

Is tape player operating normally?

Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly D1–ground

Radio receiver assembly D5–ground

Woofer amplifier faulty.

Is there continuity between the following terminals
with connector disconnected?

Radio receiver amplifier D1 – Woofer amplifier 1

(Power amplifier C1)

Radio receiver amplifier D5 – Woofer amplifier 5

(Power amplifier C5)

Radio receiver assembly faulty.

Temporarily install another woofer amplifier.
Functions OK?

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

BE–231

8

Radio

RECEPTION POOR

Antenna cord faulty.

Poor signals, poor location.

Problem with radio wave signals or location?

Go to No. 32.

Check if antenna cord is OK?

Radio receiver assembly faulty.

9

Radio

PRESET MEMORY DISAPPEARS

Wire harness or connector faulty.

Radio receiver assembly faulty.

Is terminal A4 of radio receiver assembly
properly connected?

BE–232

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

10

Radio

VOLUME REMAINS AT MAXIMUM LEVEL

A. without CD player type

Wire harness faulty.

Radio receiver assembly faulty.

Is tape player operating normally?

Is there continuity between the following terminals
with connector disconnected?

Radio receiver amplifier B1 – Power switch 14

Radio receiver amplifier B3 – Power switch 11

Power switch faulty.

Radio receiver assembly faulty.

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

?

B. with CD player type

Wire harness faulty.

Radio receiver assembly faulty.

Is tape player operating normally?

Is there continuity between the following terminals
with connector disconnected?

Radio receiver amplifier B1 – Power switch 14

Radio receiver amplifier B3 – Power switch 11

Power switch faulty.

Radio receiver assembly faulty.

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

?

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

BE–233

11

Tape player

CASSETTE TAPE CANNOT BE INSERTED

A. without CD player type

Wire harness faulty.

Radio receiver assembly faulty.

Is there continuity between the following terminals
with connector connected?

Radio receiver amplifier A3 – ground

Radio receiver amplifier A4 – ground

Radio receiver assembly faulty.

Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly A7 – ground

Replace fuse.

Wire harness faulty.

Remove foreign object.

Is there a foreign object inside tape player?

Is radio operating normally?

Check if RADIO No. 1 and RADIO No. 2 fuses
are OK.

BE–234

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM