Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT FUSE (RADIO NO. 1, RADIO NO. 2, AM1)
1. Remove the RADIO NO. 1 fuse from the engine room No. 1 relay block.
2. Remove the RADIO NO. 2 fuse from the passenger side junction block.
3. Remove the AM1 fuse from the driver side junction block.
4. Measure the resistance of the fuses.
  Standard resistance:
  
  Below 1 Ω
NG: REPLACE FUSE

OK: Go to next step

CHECK WIRE HARNESS (STEREO COMPONENT AMPLIFIER - BATTERY AND BODY GROUND)

Disconnect the S22 and S23 amplifier connectors.

Fig 1: Identifying S22 And S23 Amplifier Connectors Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance and voltage of the wire harness side connectors.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
S22-13 (GND) - Body ground	Below 1 Ω
S22-12 (E) - Body ground	Below 1 Ω

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
S22-7 (+B) - Body ground	Always	10 to 14 V
S22-16 (+B) - Body ground	Always	10 to 14 V
S23-20 (ACC) - Body ground	Ignition switch ACC	10 to 14 V

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE