Premium Sound

Radio Control Knob/LCD Display Illumination

The Instrument Panel Dimming Rheostat controls the brightness of the Electronic Radio control knob illumination bulbs, as well as the brightness of the LCD time/frequency display.

With the Ignition Switch in ACC or RUN, voltage is present at the Instrument Panel Dimming Rheostat through the RADIO Fuse and circuit 600 (DB/BK). With the Main Light Switch turned to OFF, the Instrument Panel Dimming Rheostat applies battery voltage at C257, pin D of the Electronic Radio and the LCD display is illuminated at full brightness.

With the Main Light Switch in PARK or HEAD, the Rheostat: 1) reduces voltage to C257, pin D, to reduce LCD display illumination brightness, and 2) applies voltage to C257, pin E, to illuminate the Electronic Radio control knob illumination bulbs.

Premium Sound

Voltage is present at C280, pin H of the Electronic Radio at all times through the ROOM Fuse and circuit 220 (DB/R). This provides constant power to the Radio clock and station preset memory circuits.

With the Ignition Switch in ACC or RUN, voltage is also present at the Electronic Radio and the Premium Sound Amplifier through the RADIO Fuse and circuit 600 (DB/BK).

When the Electronic Radio is turned on, current flows through the RADIO Fuse, circuit 600 (DB/BK), and the Electronic Radio circuits to ground. The Electronic Radio then applies voltage to C282, pin C, of the Premium Sound Amplifier on circuit 630 (R/BK). The Radio and Amplifier turn ON.