On mine, there are two hot wires and two other wires. One of the other wires seems to go to the engine/ignition/fuel, and the other seems to go to auxiliary electrical components (headlights, tail lights, etc.). I had to figure them out when I installed my winch last week. I didn't put a whole lot of time into what all they run, I was just looking for a switched voltage source for my winch buttons. I measured the two hots with a meter, and they are always hot, then jumped one to each of the other two wires. One of the two makes the fuel pump run, the other turns on the headlights (so I'm guessing ignition & accessory, respectively).