AUDIO AND VISUAL SYSTEM > Microphone Circuit between Microphone and Radio Receiver

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DESCRIPTION

This circuit sends a microphone signal from the microphone to the radio receiver.
It also supplies power from the radio receiver to the microphone.

WIRING DIAGRAM


E173180E01


INSPECTION PROCEDURE

1.INSPECT RADIO RECEIVER ASSEMBLY


    E173181E02
  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    Switch Condition
    Specified Condition
    3 (MACC) - Body ground
    Ignition switch on (ACC)
    4 to 6 V


NG
REPLACE RADIO RECEIVER ASSEMBLY
OK


2.CHECK HARNESS AND CONNECTOR (OVERHEAD JUNCTION BLOCK [MICROPHONE] - RADIO RECEIVER)


    E173182E02
  1. Disconnect the R8 overhead junction block (microphone) and E102 radio receiver connectors.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    Specified Condition
    E102-3 (MACC) - R8-12 (ACC)
    Below 1 Ω
    E102-2 (MIN+) - R8-11 (MI1+)
    Below 1 Ω
    E102-5 (MIN-) - R8-10 (MIC-)
    Below 1 Ω
    E102-3 (MACC) - Body ground
    10 kΩ or higher
    E102-2 (MIN+) - Body ground
    10 kΩ or higher
    E102-5 (MIN-) - Body ground
    10 kΩ or higher
    E102-6 (SGND) - Body ground
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE