Radio, Stereo, and Compact Disc: Description and Operation

CIRCUIT OPERATION
The Radio receives its power at all times through the ELEC Fuse to sustain memory for the clock and station presets. It receives battery voltage with the Ignition Switch in "ACC" or "RUN" through the Radio Fuse, which turns on the Radio.

COMPACT DISC AND CASSETTE PLAYER
If equipped, the Compact Disc or Cassette Player is part of the Radio Unit. When operating, the same power required by the Radio is necessary for Tape or Disc Player operation.

AMPLIFIER (GRAND PRIX)
The Amplifier is controlled by the Radio. When the Radio is turned on, battery voltage from the Radio is applied to the Amplifier, enabling the Amplifier and turning on the Front Door Speakers. When the Radio is turned off, battery voltage is removed from the Amplifier, turning it off.

AMPLIFIER (STE)
The Amplifier is controlled by the Radio. When the Radio is turned on, battery voltage from the Radio is applied to the Amplifier, enabling the Amplifier and turning on the Subwoofers. Amplifier gain is controlled by the Gain Control in the Gain Control Switch. Variable voltage is fed back to the Amplifier. This voltage controls amplification of the Subwoofers in the Rear Speakers. The Amplifier receives signals from all four speaker channels of the Radio. The Amplifier filters and amplifies only the low frequency portion of the Radio output and sends a one channel (mono) signal to both of the Subwoofer Speakers through the subwoofer output. People cannot distinguish the direction of low frequency sounds, so stereo amplification for the Subwoofers is unnecessary. Since the Amplifier receives signals from all four channels, the Subwoofers work at the same power level no matter where the balance controls may be positioned.

ILLUMINATION
With the Radio turned on, the VF display lights to a fixed brightness. When the Park Lights or Headlights are turned on, battery voltage is applied to the "lights on input" of the Radio and the VF display dims to the present dimmer control setting. With the lights on, the Radio receives a Pulse Width Modulated (PWM) illumination signal from the Light Switch. The PWM signals control the VF Radio illumination which varies as the dimmer control is adjusted. The Radio buttons and face illumination is incandescent. They light when the lights are turned on, receiving power from the panel light input. The incandescent illumination brightness is controlled by the variable voltage panel light input.