How do you install fog lights on a Scion FRS? (video)
How do you turn on the fog lights? (video)
Do you need a relay for fog lights?
Relays are an important component in wiring fog or driving lights with a 30-60A draw. Basically, the relay protects the switch from getting hot and creating unwanted resistance. The low current through the switch triggers the relay to make a higher current connection to the heavy load of the fog lights. via