The FOG LAMP relay in the top underhood accessory wiring junction block controls the fog lamps. The coil and switched side of the relay receives B+ at all times from the Fog Lamp Relay Fuse. When the fog lamp switch is pressed, a ground is applied to the BCM through the fog lamp switch input circuit. The BCM then applies a ground to the FOG LAMP relay through the fog lamp relay coil control circuit. This energizes the relay, closing the switched contact and applies B+ to the fog lamps turning them on. The fog lamps receive a constant ground.