Normal Operation
WARNING: This page is about a different car, the 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Voltage is supplied to the headlamp switch through circuit 195 (TN/WH). When the headlamp switch is in the parking lamps or headlamps ON position, voltage is sent to the instrument panel dimmer switch, from the headlamp switch, on circuit 14 (BN). Using electronic circuitry, the instrument panel dimmer switch generates a variable pulse width modulated (PWM) signal that is sent to the instrument cluster and dimmable switches on circuit 19 (LB/RD).