Fog/Driving Lamp: Description and Operation

FOG LAMPS

With the ignition switch in the ON position, and the park lamps or low beam headlights ON, the fog lights will illuminate when the driver presses the fog lamp switch. The PARK fuse in the underhood accessory wiring junction block, supplies battery positive voltage to the headlamp switch. When the headlamp switch is in the PARK or HEAD position battery positive voltage is applied to the park lamp supply voltage circuit. The park lamp supply voltage circuit is then applied to the fog lamp switch. When the fog lamp switch is pressed, the fog lamp switch applies battery positive voltage to the fog lamp relay coil supply voltage circuit. The fog lamp relay coil supply voltage circuit is then applied to the fog lamp relay coil side in the underhood fuse block. The ground for the fog lamp relay is applied from the G101 through the high beam headlamps to the coil side of the fog lamp relay. This energizes the relay, closing the switch contacts. The FOG LP fuse in the underhood fuse block applies battery positive voltage to the switched side of the fog lamp relay. When the relay is energized the current flow is now from the fog lamp relay to both front fog lamps. The ground for the fog lamps is applied from G101. The state of the fog lamps either ON or OFF will remain the same until the front fog lamp switch is pressed again, or the ignition switch is cycled OFF and ON. The park lamps or low beam headlights must be ON in order for the fog lights to be illuminated. Fog lamp operation will be cancelled whenever the park lamps, are turned OFF or the high beam headlights have been selected.

The rear fog lamps are controlled in much the same way, however the front fog lamps must be on in order to turn on the rear fog lamps. The rear fog lamps have there own relay, and both the relay control and current flow are the same.