The fog lights on a BMW E36 are an important aspect of the car's lighting system, particularly if you live somewhere where the weather is often foggy and or rainy. Owners also often elect to upgrade to better fog lights like HID (High Intensity Discharge) lights for better visibility. Replacing and rewiring an aftermarket set of lights is quite easy if you follow these steps.
Open the hood and locate the backs of the fog lights in the front of the engine bay. Insert a narrow tool like a screwdriver through the hole that's adjacent to the fog light housing. Push the screwdriver against the clip that holds the fog light in place to release it. Make sure the fog light does not fall out when you release it.
Cut the wire of the new fog light bulbs so there are about two inches left.
Remove the OEM bulb from the fog light housing and cut the wires to the bulb, leaving the wires on the inside of the bulb connector.
Solder the wires from the inside of the bulb connector to the new bulbs. Cover the wires with electrical tape or heat shrink. Reassemble the fog light.
Cut the wires on the ballast that lead to the bulb if the new lights come with a ballast.
Cut the OEM fog light connectors of the car, leaving enough wire to work with.
Solder the ballasts to the fog light connectors on each side of the car, paying attention to the colors of the wires. Cover the wires with tape.
Hook up the new connections and check to make sure that the fog lights turn on.
