GM Service Manual Online
For 1990-2009 cars only

For THEFTLOCK Anti-Theft feature or for radio features and control operations refer to Radio/Audio System Operation-Theftlock

The radio receives battery voltage at all times circuit 640 from the PWR ACCY Fuse 7 to keep clock and preset station memory enabled when the ignition is off. With the ignition switch in the ACCY position, the RUN position or during Retained Accessory Power (RAP), voltage is applied from the RADIO Fuse 17 to enable radio operation.

When the park lights or the headlights are turned on, voltage is applied to the radio from the headlamp switch in order to illuminate the display. With the headlights or the park lights on, the radio display may be dimmed manually using the IP dimmer switch. The IP dimmer switch varies the voltage on to the radio to control display dimming.

Speakers: Chevrolet UQ0 and Pontiac W53, W54, W55 Entertainment Systems

With the base speaker system, the audio signals are amplified within the radio, and the output signals go directly to the speakers.

Speakers: Chevrolet UZ7 (6 Speaker Sound System)

All radio audio output signals are connected directly to the amplifier. All of the 6 speakers in the system are connected to the amplifier outputs and are driven by the amplified radio audio signals. The amplifier is used to drive two rear extended range speakers, two rear subwoofers, and two front speaker assemblies consisting of one tweeter and one midrange speaker.

Speakers: Chevrolet U59 Entertainment System (8 Speaker -- Convertible Only)

All radio output signals are connected directly to the amplifier. The eight speakers in the system are connected to the amplifier outputs and are driven by the amplified radio audio signals. The amplifier is used to drive two front speaker assemblies consisting of one tweeters and one midrange each and two rear speaker assemblies consisting of one tweeter and one subwoofer each.

Speakers: Pontiac W54 and W55 Entertainment Systems (10 Speaker Sound System)

Radio audio output signals for two front tweeters and two rear tweeters are amplified within the radio, and the output signals go directly to the speakers.

All radio audio output signals are also connected to the amplifier. The other six speakers in the system are connected to the amplifier outputs and are driven by the amplified radio audio signals. The amplifier is used to drive two front midrange speakers, two rear midrange speakers, and two rear subwoofers with dual voice coils.