Radio, Stereo, and Compact Disc: Description and Operation
Important:^ For DELCO-LOC II Anti-Theft feature (available only on Chevrolet U1C and U1T Disc Radio options) or for Radio Features and Controls Operations, refer to Accessory and Optional Equipment. Antitheft and Alarm Systems
^ For THEFT-LOC Anti-theft Feature (available on all Pontiac Radio Options) or for Radio Features and Controls Operation, refer to Accessory and Optional Equipment.
The Radio receives battery voltage at all times on CKT 640 from Power Accessory Fuse 7 to keep clock and preset station memory alive when the Ignition is "OFF". With the Ignition Switch in "ACCY," "RUN" or "RETAINED ACCESSORY POWER (RAP)," voltage is applied to CKT 43 from RADIO Fuse 17 to enable Radio operation.
When the Park Lights or Headlights are turned "ON," voltage is applied to the Radio on CKT 9 from the Headlight Switch. When voltage is applied to CKT 9 at the Radio, the Radio will illuminate the display. With the Headlights or Park Lights "ON," the Radio display may be dimmed manually using the I/P Dimmer Switch. The I/P Dimmer Switch varies the voltage on CKT 8 to the Radio to control display dimming.
SPEAKERS: (UQ0, U62 OR UW6)(CHEVROLET)),(W51, W52, W53, W54, W55, W58, W57 Entertainment Systems)(PONTIAC)
With the Base Speaker System, the audio signals are amplified within the Radio, and the outputs go directly to the speakers.
SPEAKERS: DELCO-BOSE U65)
The Delco-Bose-Music System is a five-speaker system consisting of two front speakers, two rear subwoofers, and one rear speaker. A relay is used to control Battery voltage to three speaker/amps assemblies. Rear speaker/Amp Assembly has one amplifier for the rear speaker and a separate amplifier for the rear subwoofers. Assembly are also shielded. A shielded cable carries the audio signals from the Radio to the speaker/amps where the signals are then amplified to drive the speakers. The subwoofer audio signals from the rear speaker/amp assembly are also shielded.
SPEAKERS: W54, W55, W56 Entertainment Systems (10 SPEAKER SOUND SYSTEM)
For eight of the system's ten speakers, the audio signals are amplified within the Radio and the outputs go directly to the speakers.
The Amplifier is used to drive two subwoofers. The Amplifier receives all the amplified signals coming from the radio. These signal are used to determine the Amplifier's output to the subwoofers. The Amplifier has separate power and ground inputs.
STEERING WHEEL RADIO CONTROL SWITCHES
The Steering Wheel Control Switches control Radio power, volume and station frequency. These switches are actually a ladder network consisting of the switches and a series of resistors. The ladder network is arranged so that each switch has a different resistance. This allows a different voltage output to the Radio for each switch pressed.
The Steering Wheel Control (SWC) Switches use incandescent backlighting. The illumination signal CKT 8 is a Pulse Width Modulated (PWM) signal from the Headlight Switch. The bulbs are serviceable.
SIR COIL ASSEMBLY
The SIR Coil Assembly contains four wires used by the Steering Wheel Controls. This allows voltage to be sent from the Steering Wheel Switches to the Radio while the Steering Wheel is being turned.