Circuit Operation - Interior Lights Dimming

The I/P Dimmer Switch controls the brightness of the incandescent lamps and Vacuum Fluorescent (VF) displays. The incandescent lamps are located in various components (see schematics) and the VF displays are located in the Radio.

Incandescent Dimming
The brightness of the incandescent lamps is determined by a variable voltage signal produced by the Headlamp Switch.

Vacuum Fluorescent (VF) Dimming
The brightness of the Vacuum Fluorescent (VF) Displays is controlled by two signals: the VF Dim Displays Signal (CKT 308) and the VF Dimming Signal (CKT 230). With the Park Lamps ON (VF Dim displays CKT 308) the VF display of the Radio will dim for nighttime viewing. When the VF Dim Displays Signal is not present (Park Lamps OFF), the VF displays are at high brightness for daytime viewing. When the Park Lamps are ON, the Headlamp Switch provides a Pulse Width Modulated (PWM) signal (VF Dimming Signal CKT 230) which controls the brightness of the VF displays when the I/P Dimmer Switch is adjusted.