Front-facing fog lights and fog lamps are a type of automotive headlight that is designed to emit light in a bar-shaped beam. The beam is typically designed to have a sharp cutoff on top, and the actual lights are usually installed low and aimed toward the ground at a sharp angle. The position and orientation of fog lights can be compared and contrasted with high beam and low beam headlights to reveal exactly how different these seemingly similar devices are. High beam and low beam headlights are both aimed at a relatively shallow angle, which allows them to illuminate the road surface a great distance in front of a vehicle. In contrast, the sharp angle used by fog lights means that they only illuminate the ground immediately in front of a vehicle.
Disconnect the negative battery terminal.
Lay the wiring harness in the engine bay, approximating the layout you want. The wiring needs to be routed so it will avoid spinning parts or the hot exhaust areas.
Remove the interior panels under the steering wheel. The left side is usually a fuse access panel that pulls off by hand, while the panel below the steering column needs bolts removed.
Choose a location for the off/on switch.
Look for other ground wires or a bolt going through metal. Remove the bolt and slide in ground connector before re-tightening the bolt.
The interior fuse box cover usually has a helpful diagram, and it may list a spare accessory location. If not, use a voltmeter to find an empty fuse location that only has 12V power when the engine is on, and plug in the positive connector.
Run wiring from the engine bay through the firewall.
Connect the off/on switch wiring to the engine bay wiring, then use the cable ties to bundle the extra length of wire and tuck it out of the way.
Run the fog light connections down to where the fog lights will be.
Connect the positive lead to the positive battery terminal. The ground can be bolted to the frame or engine block.
Connect the fog lights to the wiring harness.