headlights

Basically, the relays handle all the high voltage draw and are placed closer to the headlights. It only takes a small voltage signal from your headlight switch to engage the heavy-duty relay, therefore you are not relying on running the high draw voltage through your old crusty wiring and headlight switch.

Same principle is used to run the high amp electric fans.

There ya go...relays for dummies (like me).

To The original poster, the lights and setup CrackedBack speaks of are really great!