AM/FM Stereo

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.


AM/FM Stereo

Voltage is present at C257, pin H of the Electronic Radio at all times through the ROOM Fuse and circuit 330 (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 C257, pin F of the Electronic Radio 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 Radio turns ON.