Radio/Audio System Circuit Description Except Luxury

Voltage is supplied at all times from the RADIO BATT Fuse 19 through CKT 1140 (GRY)). This voltage feeds both radio presets and clock memory. Ignition and accessory voltage is supplied through CKT 43 (YEL) from the RADIO Fuse 17. CKT 43 (YEL) enables the radio to operate when turned on. Voltage used for dimming control is supplied through CKT 8 (GRY) from the Headlamp and Panel Dimmer Switch. When this voltage is supplied, the display intensity is controlled by the Headlamp and Panel Dimmer Switch. Lights in the unit operate at full brightness from audio system voltage until a signal is supplied from the Headlamp and Panel Dimmer Switch. CKT 1382 (PPL/WHT) is connected to the Parade Mode Switch located in the Headlamp and Panel Dimmer Switch. When the voltage is supplied through CKT 1382 (PPL/WHT), the display lighting intensity is restored to full brightness. Grounding for the unit is through Ground G200 through CKT 150 (BLK).

Speaker control is supplied through two CKTs per channel. Each channel contains one positive and one negative output to feed the AC signal which activates the driver in the speaker. The outputs for the speakers are as follows.

CKT 817 (DK GRN/WHT) is an input to the radio from the VCM (Gas) or Vehicle Speed Sensor (Diesel). This signal varies with vehicle speed which commands the radio to increase or decrease the volume proportionately to vehicle speed.

When the radio is turned on, CKT 314 (PNK) supplies voltage to the Power Amp Relay coil feed. CKT 150 (BLK) then grounds the Power Amp Relay coil to complete the CKT. When the Power Amplifier Relay is energized, voltage supplied to the Power Amplifier Relay from CIG LTR Fuse 13 supplies voltage through CKT 640 (ORN) to activate the Power Amplifier. The Power Amplifier grounds through CKT 150 (BLK) to Ground G202. The Power Amplifier receives input signals from the Left Rear and Right Rear speaker channels. The Amplifier then sends these signals as outputs as follows:

Power is supplied to the Remote Playback Unit by CKT 1140  (ORN) from the radio. This voltage is used to operate the unit. CKT 314 (PNK) is a voltage source supplied by the radio when the Remote Playback Unit is commanded on. Grounding for the unit is provided through Ground G202 through CKT 150 (BLK). CKT 1407 (GRN) is the right output signal and CKT 1406 (ORN/BLK) is the left output. These CKTs are used to supply the signal to the radio. CKT 1405 (TAN) provides the common neutral required to complete the CKT for the outputs. CKT 514 (BARE) supplies a shielded ground to the outputs so as to prevent interference to the output signal. Dimming control of the unit is through CKT 8 (GRY) from the radio. When this voltage is supplied, the display intensity is controlled by the Headlamp and Panel Dimmer Switch. CKT 855 (DK GRN) is used to provide a link of data communication between the radio and the remote playback unit.

Radio/Audio System Circuit Description Luxury

Voltage is supplied at all times from the RADIO BATT Fuse 19 through CKT 1140 (GRY)). This voltage feeds both radio presets and clock memory. Ignition and accessory voltage is supplied through CKT 43 (YEL) from the RADIO Fuse 17. CKT 43 (YEL) enables the radio to operate when turned on. Voltage used for dimming control is supplied through CKT 8 (GRY) from the Headlamp and Panel Dimmer Switch. When this voltage is supplied, the display intensity is controlled by the Headlamp and Panel Dimmer Switch. Lights in the unit operate at full brightness from audio system voltage until a signal is supplied from the Headlamp and Panel Dimmer Switch. CKT 1382 (PPL/WHT) is connected to the Parade Mode Switch located in the Headlamp and Panel Dimmer Switch. When the voltage is supplied through CKT 1382 (PPL/WHT), the display lighting intensity is restored to full brightness. Grounding for the unit is through Ground G200 through CKT 150 (BLK).

Signal from the Rear Stereo Controller, located in the Floor Console, comes through CKT 1011 (LT GRN) allowing the rear passengers to control the functions of the radio from the rear seats. In order for the Audio Amplifier and Rear Stereo Controller to be used, they must receive an enable signal from the radio through CKT 314 (PNK). CKT 835 (DK GRN) connects the radio to the Data Link Connector (DLC). The Power Antenna feed between the Radio and the Audio Amplifier runs through CKT 145 (DK GRN).

Front Speaker outputs from the Radio to the Audio Amplifier are as follows:

Rear Speaker outputs from the Radio to the Audio Amplifier are as follows:

The Radio is also connected with the Vehicle Communications Unit (VIU), through CKT 1407 (LT GRN) for the Right In and CKT 1406 (ORN/BLK). The Audio Common is CKT 1405 (LT BLU), and CKT 514 (Bare Wire) is the Drain Wire. The purpose for this is to have the 3 button OnStar system operate through the stereo speakers by cancelling the signal from the CD Player and/or CD Changer.

CKT 817 (DK GRN/WHT) is an input to the radio from the VCM (Gas) or Vehicle Speed Sensor Buffer (Diesel). This signal varies with vehicle speed which commands the radio to increase or decrease the volume proportionately to vehicle speed.

The Bose® Amplifier, contained in the center floor console, boosts the sound of the seven speakers equipped in the vehicle. Power is supplied to the amplifier from the CIG LTR fuse 13 through CKT 640 (ORN). However the amplifier is not on unless a signal is received from the radio controller through CKT 314 (PNK). Ground for the amplifier runs to G202 through CKT 150 (BLK).

The Left Front Speaker In from the radio comes through CKT 511 (TAN); Right Front Speaker In comes through CKT 1874 (LT BLU). Front Speaker Common runs through CKT 1948 (LT GRN). The Right Rear In from the radio comes through CKT 46 (DK BLU); Left Rear Speaker In comes through CKT 199 (BRN). Rear Speaker Common runs through CKT 116 (YEL). The Power Antenna between the amplifier and radio runs through CKT 145 (DK GRN). Circuits 367 (BRN/WHT), 372 (BLK/WHT), and 368 (DK GRN/WHT), link the audio amplifier to the rear stereo controller.

Power for the Subwoofer runs through CKT 346 (DK BLU/WHT), ground, through CKT 1794 (LT GRN/WHT). Drain for the Subwoofer runs through CKT 514. Power for the Left Rear Tweeter runs through CKT 1859 (TAN), ground, through CKT 1959 (WHT). Power for the Right Rear Tweeter runs through CKT 1855 (TAN), ground, through CKT 1955 (RED). Power to the Left Front Door Speakers runs through CKT 201 (TAN), ground, through CKT 118 (GRY). Power to the Right Front Door Speakers runs through CKT 200 (LT GRN), ground, through CKT 117 (DK GRN). The Right Rear Headliner Tweeter receives power through CKT 1854 (WHT), ground, through CKT 1949 (YEL). The Left Rear Headliner Tweeter receives power through CKT 1858 (RED), ground, through CKT 1958 (PPL).

The CD Player is a single disk unit, mounted in the dash below the radio, connected to a six disk CD Changer, contained in the center floor console. These two units receive power when the radio is on. The CD Player's power comes through CKT 180 (BRN), while the Changer receives power through CKT 1140 (ORN). Grounds for both units go to the radio through CKT 150 (BLK). Circuits connecting the CD Player and CD Changer to the radio are the same circuits used for the Vehicle Interface Unit (VIU). The dimming function for the CD Player comes through CKT 8 (GRN) and is fed from the radio. Data link between the CD Player/CD Changer and the radio runs through CKT 835 (DK GRN).