Allante V8-273 4.5L (1991)
Dimmer Switch: Description and Operation
CIRCUIT OPERATION
The Body Computer Module (BCM) generates two types of dimming signals: one for the incandescent bulbs (keyboard backlighting) and another for
the LCD displays.
These two pulse width modulated (PWM) dimming signals are based upon the ambient light conditions sensed by the Twilight Photocell, the
Instrument Panel Dimming Control setting, and the Park Lights and Headlight inputs. The ECM detects these inputs and generates the corresponding
outputs for the LCD displays and keyboard backlighting.