Schematic Reference: Radio/Audio System Schematics .

Review the Diagnostic Starting Point - Entertainment .

Important: The following information lists the most probable cause of the concern to the least probable cause. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with replacement. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems.

Important: The following information lists the most probable cause of the concern to the least probable cause followed by the appropriate test for that condition. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with the replacement. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

With RPO UM8

1. Battery positive voltage circuit to the amplifier open. Test the battery positive voltage circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Ground circuit to the amplifier open. Test the ground circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
3. Speaker output from the radio shorted. Test each speaker output of the radio for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
4. No audio output from the amplifier. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

Important: The following information lists the most probable cause of the concern to the least probable cause. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with replacement. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Without RPO UQ7

1. Speaker output open. Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. No audio output from the radio. Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to 50 percent. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the radio. Refer to Radio Replacement .

With RPO UQ7

1. Speaker output circuit from amplifier open. Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. No audio output from the amplifier. Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to 50 percent. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

1. Make sure the Rear Seat Audio control is turned OFF.
2. Test for less than 1-volt on the radio on signal at the Rear Seat Audio control. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. If more than 1-volt repair the short to voltage on the radio on signal.
3. Test for the AC audio signal voltage on the appropriate speaker circuit at the input to the Rear Seat Audio control. If the input AC signal voltage is not there, repair the cause .
4. Test for the AC audio signal voltage on the appropriate speaker circuit at the output of the Rear Seat Audio control. If the input AC signal voltage is not present. Test the speaker circuit for a short to ground. If no short is present replace the Rear Seat Audio control. Refer to Rear Seat Audio Control Replacement .

Important: The following information lists the most probable cause of the concern to the least probable cause. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with replacement. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

With RPO UQ7

1. Speaker output circuit from amplifier shorted. Test the appropriate speaker output circuits for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

Front Speakers Inoperative

1. Speaker output circuit from amplifier shorted. Test the appropriate speaker output circuits for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

Rear Speakers Inoperative

1. Speaker output circuit from amplifier shorted. Test the appropriate speaker output circuits for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .