I almost forgot, the Red wire and the Brown wire complete the circuit to allow the electric starter switch to excite. Once those 2 wires are "switched" or "jumped" it is as if the key was in the "on" position. The 2 black wires when connected are a kill switch. SO, when the stock key ignition switch is turned to the off position, the engine shuts off. Since I eliminated the key ignition switch and used only a rocker switch, the kill switch feature was not needed as the bike already has a handlebar mount kill switch. Because I didn't need the wires, I just taped them up.