3 ways you can do it. Either cut into the harness to splice it basically right where the light is mounted. 2 run the wires to the headlight switch. Or 3, this is what I did, just splice them into the tail light wires. My tail light wires on the harness side were good. So all I did was use round spades on the lights themsleves and plugged em in to the factory round spades. Do yourself a favoir, don't use scotch locks, they suck.