Dashboard / Instrument Panel: Description and Operation

OPERATION
Voltage is present at the coil and contacts of the Park Lamp Relay at all times through the TAIL Fuse.

Electronic Radio Illumination
With the Ignition Switch in "ACC" or "RUN", voltage is present at pin H of the Instrument Panel Dimming Module through the RADIO Fuse.

With the Main Light Switch in "OFF", the Park Lamp Relay is not energized and voltage is not present at pin D of the Instrument Panel Dimming Module. With this input information, the Module applies voltage at pin F to power the Electronic Radio LCD at full brightness for daytime visibility.

If the Main Light Switch is placed in "PARK" or "HEAD", the Park Lamp Relay is energized and voltage is now present at pin D of the Instrument Panel Dimming Module. The Module now reduces voltage at pin F to dim the LCD display.

At the same time, the Module applies voltage at pin B to illuminate the Electronic Radio control knobs, making them visible at night.

The voltage applied to pin B is variable and is determined by the position of the Module dial.

All Other Illumination Bulbs
With the Ignition Switch in "ACC" or "RUN", voltage is present at the Instrument Panel Dimming Module through the RADIO Fuse.

With the Main Light Switch in "PARK" or "HEAD", the Park Lamp Relay is energized and voltage is present at all instrument, switch, and control illumination bulbs through circuit 301 (R/BK).

Voltage is also present at pin D of the Instrument Panel Dimming Module through the same circuit.

Since all illumination bulbs are grounded through circuit 305 (R) and the Module, the Module can determine bulb brightness by varying the resistance between pins A and G. The resistance between pins A and G is determined by the position of the Module dial.