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Home >> Hummer >> 2008 >> H3 Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 168 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Speaker Malfunction >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

Amplifier Circuit Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the audio amplifier.
  2. Ignition OFF, test for less than 10 ohms between the ground circuit terminal 8 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 4 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the circuit fuse is open, replace the audio amplifier.
  4. Ignition OFF, disconnect the X3 harness connector at the audio amplifier.
  5. Radio ON, test for 0.6-1.0 volts between the amplifier control circuit terminal 11 and ground.
    • If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the radio.
    • If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  6. If all circuits test normal, replace the audio amplifier.

Speaker Circuit Malfunction

  1. Ignition OFF, inspect the appropriate speaker and the surrounding interior trim for proper and secure mounting. Improper speaker mounting or loose trim may cause an audible buzz or distortion.
    • If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item.
  2. Disconnect the X3 and X4 harness connectors at the audio amplifier.
  3. Ignition ON, radio ON, test for 5.0-7.5 volts between the appropriate audio signal circuit terminal listed below and ground.
    • Left front low level - Connector X3, terminal 11
    • Left front low level - Connector X3, terminal 12
    • Right front low level - Connector X3, terminal 3
    • Right front low level - Connector X3, terminal 4
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
    • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  4. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    • Left rear low level - Connector X4, terminal 12
    • Left rear low level - Connector X4, terminal 11
    • Right rear low level - Connector X4, terminal 4
    • Right rear low level - Connector X4, terminal 3
    • Center channel low level - Connector X4, terminal 14
    • Center channel low level - Connector X4, terminal 13
    • Sub woofer low level - Connector X4, terminal 6
    • Sub woofer low level - Connector X4, terminal 5
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
    • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  5. Ignition OFF, connect the X3 and X4 harness connectors at the audio amplifier.
  6. Disconnect the harness connector at the inoperative speaker.
  7. Ignition ON, radio ON, test for 5.0-7.5 volts between the inoperative speaker output positive (+) circuit and ground.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier.
    • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the audio amplifier.
  8. Ignition ON, radio ON, test for 5.0-7.5 volts between the inoperative speaker output negative (-) circuit and ground.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier.
    • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the audio amplifier.
  9. If all circuits test normal, test or replace the inoperative speaker.
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