Lexus SC300 / Lexus SC400. Manual — part 153

B. with CD player type

Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly B1–Power switch 14

Radio receiver assembly B3–Power switch 11

Is tape player operating normally?

Power switch faulty.

Wire harness faulty.

Is resistance value about 50 k

between termi-

nals is B3–B6 of radio receiver assembly?

Wire harness faulty.

Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly A1–Power amplifier A6

Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly B6–Power switch 13

Power switch faulty.

Wire harness faulty.

Is there battery positive voltage between the follow-
ing terminals with connector connected?

Power amplifier A14–ground

Power amplifier B10–ground

Is there battery positive voltage between the follow-
ing terminals with connector connected?

Power amplifier A6–ground

Radio receiver assembly faulty.

When the volume switch is turned from mini-
mum to maximum, does resistance between
terminals B1–B3 of radio receiver assembly
change from 0 to 50 k

?

Wire harness faulty.

Power amplifier faulty.

Is there continuity between the following terminals
with connector disconnected?

Power amplifier B7–ground

Radio receiver assem-
bly faulty.

Wire harness faulty.

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BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

BE–223

3

Radio

NOISE PRESENT, BUT AM–FM NOT OPERATING

Go to No. 32

Radio receiver assembly faulty.

BE–224

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

4

Radio

ANY SPEAKER DOES NOT WORK
(EXCEPT WOOFER)

A. without CD player type

Is there continuity between the following terminals
with connector disconnected?

Fr:

Radio receiver assembly A1–FR speaker 1
Radio receiver assembly A5–FR speaker 2

FL:

Radio receiver assembly A2–FL speaker 1
Radio receiver assembly A6–FL speaker 2

RR:

Radio receiver assembly C1–RR speaker 1
Radio receiver assembly C3–RR speaker 2

RL:

Radio receiver assembly C2–RL speaker 1
Radio receiver assembly C6–RL speaker 2

Is there continuity between the following terminals
with connector disconnected?

FR:

Radio receiver assembly A1–ground
Radio receiver assembly A5–ground

FL:

Radio receiver assembly A2–ground
Radio receiver assembly A6–ground

RR:

Radio receiver assembly C1–ground
Radio receiver assembly C3–ground

RL:

Radio receiver assembly C2–ground
Radio receiver assembly C6–ground

Wire harness faulty

(The wire harness for the FR speaker passes

through the transceiver, so the transceiver side
should be checked)

Wire harness faulty

(The wire harness for the FR speaker passes

through the transceiver, so the transceiver side
should be checked)

Speaker faulty.

Radio receiver assembly faulty.

Is tape player operating normally?

Temporarily install another speaker.
Finctions OK?

Radio receiver assembly faulty.

–

BODY ELECTRICAL SYSTEM

AUDIO SYSTEM

BE–225

Is there continuity between the following terminals
with connector disconnected?

Fr:

Radio receiver assembly B1–FR speaker 1
Radio receiver assembly B5–FR speaker 2

FL:

Radio receiver assembly B2–FL speaker 1
Radio receiver assembly B6–FL speaker 2

RR:

Radio receiver assembly B3–RR speaker 1
Radio receiver assembly B4–RR speaker 2

RL:

Radio receiver assembly B8–RL speaker 1
Radio receiver assembly BP–RL speaker 2

Is there continuity between the following terminals
with connector disconnected?

FR:

Radio receiver assembly B1–ground
Radio receiver assembly B5–ground

FL:

Radio receiver assembly B2–ground
Radio receiver assembly B6–ground

RR:

Radio receiver assembly B3–ground
Radio receiver assembly B4–ground

RL:

Radio receiver assembly B8–ground
Radio receiver assembly B9–ground

Wire harness faulty

(The wire harness for the FR speaker passes

through the transceiver, so the transceiver side
should be checked)

Wire harness faulty

(The wire harness for the FR speaker passes

through the transceiver, so the transceiver side
should be checked)

Speaker faulty.

Radio receiver assembly faulty.

Is tape player operating normally?

Wire harness faulty.

Temporarily install another speaker.
Functions OK?

Is there continuity between the following terminals
with connector disconnected?

FR:

Radio receiver assembly A7–Power
amplifier A1

FL:

Radio receiver assembly A6–Power
amplifier A2

RR:

Radio receiver assembly A15–Power
amplifier A7

RL:

Radio receiver assembly A14–Power
amplifier A8

Is there continuity between the following terminals
with connector disconnected?

FR:

Radio receiver assembly A7–ground

FL:

Radio receiver assembly A6–ground

RR:

Radio receiver assembly A15–ground

RL:

Radio receiver assembly A14–ground

Wire harness faulty.

only for vehicles with cellular phone

B. with CD player type

BE–226

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BODY ELECTRICAL SYSTEM

AUDIO SYSTEM