Operation CHARM: Car repair manuals for everyone.

Instrument Cluster Indicators

The instrument cluster has two front flood illumination lamps and four rear back-lighting lamps. The signal to control these instrument cluster illumination lamps is a pulse width modulated ground signal received from the instrument panel dimmer.

The duty cycle of the Pulse Width Modulated (PWM) signal is varied by the vehicle's operator rotating the knob of the instrument panel dimmer. The duty cycle varies from approximately 20% LO to 100% HI.