Stereo System, Clock or Equalizer Option

CIRCUIT OPERATION
The radio (including clock and cassette or equalizer option) receives its power from the RADIO fuse when the ignition is in "ACCY" or "RUN," and the ELEC Fuse which is hot at all times. Power from the ELEC fuse is used to keep the clock and station memory alive when ignition is turned "OFF."

The radio also receives power from the headlamp switch. When the park lamps or headlamps are turned "ON," power from CKT 308 is used to dim the station/clock display at night. Power from CKT 8 is used to vary the brightness of the panel lighting and is controlled by the headlamp switch rheostat.

The radio receives its ground from G201 and G203 and also from the grounded shield of the antenna coaxial cable.

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.

RADIO SPEAKER AMPLIFIER
The radio speaker 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. When the radio is turned "OFF," battery voltage is removed from the amplifier turning it off.

ILLUMINATION
With the radio turned on, the Vacuum Fluorescent (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 headlight 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.