Could someone please tell me the point of a relay harness in an aftermarket HID kit? My friend and I are having a disagreement on the matter. I think that the relay re-routes the power source from the alternator, directly to the battery....therefore lessening strain on the electrical system and providing steady voltage to the ballasts. My buddy thinks that it's some sort of automatic switch, that you only need in a vehicle without manual headlight controls. I'm not sure where he was coming from on that one. Neither of us are sure of the true answer, but both of us have installed our HID kits with relays and have been satisfied. Could someone that knows the answer please chime in?