Without RPO WBM

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

No audio output from the radio.

Test for any AC voltage between the left front audio signal circuits at the left front speaker connector with the radio volume adjusted to 50 percent. If no AC voltage is present, check for shorts to battery positive or shorts to ground on any speaker output circuit from the radio. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. If no shorts are located, replace the radio. Refer to Radio Replacement .

With RPO WBM

Battery positive voltage to the amplifier open.
Test the battery positive circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Ground to the amplifier open.
Test the ground circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
No low level audio output from the radio.
Test for any AC voltage between the left front low level audio signal circuits at the amplifier connector with the radio volume adjusted to 50 percent. If no AC voltage is present, check for shorts to battery positive or shorts to ground on any speaker output circuit from the radio. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. If no shorts are located, replace the radio. Refer to Radio Replacement .
No radio on signal to the amplifier
Test the radio on signal circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Defective amplifier
Replace the amplifier. Refer to Amplifier Replacement .