Always perform the Diagnostic System Check - Vehicle before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Vehicle .

Schematic Reference: Radio/Navigation System Schematics

Only Front Speakers or Only Rear Speakers Inoperative (RPO UZ6 only) or (RPO WBM only)

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

Audio output from amplifier to speaker shorted to ground or shorted to battery positive voltage.

Test the affected audio output circuits from the amplifier for a short to ground or a short to positive battery voltage. Refer to Circuit Testing and Wiring Repairs .

Without RPO UZ6 or RPO WBM

1. No audio output from the radio--Test for any AC voltage between the audio signal circuits at the affected speaker connector with the radio volume adjusted to 50 percent. If no AC voltage is present, check for shorts to battery positive voltage or shorts to ground on all speaker output circuits from the radio. If no shorts are located, replace the radio. Refer to Radio Replacement .
2. Speaker output open--Test the appropriate speaker outputs for an open. Refer to Circuit Testing and Wiring Repairs .
3. Defective speaker--Replace the appropriate speaker. Refer to Speaker Replacement Reference .

With RPO UZ6 or RPO WBM

1. Speaker output from amplifier open--Test the appropriate speaker outputs for an open. Refer to Circuit Testing and Wiring Repairs .
2. Defective speaker--Replace the appropriate speaker. Refer to Speaker Replacement Reference .
3. No audio output from the amplifier--Test for any AC voltage between the audio signal circuits at the affected speaker connector with the radio volume adjusted to 50 percent. If no AC voltage is present, check for shorts to battery positive voltage or shorts to ground on the affected speaker outputs. Refer to Circuit Testing and Wiring Repairs . If no shorts are located, replace the amplifier. Refer to Radio Speaker Amplifier Replacement .