Outer Limits 4x4 Board

just bought an X9 superwinch second hand but it has never been unspooled. however when it was pulled out much of the wiring was disconnected. with the female plug end that the hand control goes into there are three wires, black with female spade fitting on end, green with femal spade fitting on end and a white wire with an eye fitting on it. i The black and green wires obviously go to the male fillings on the solenoid but where does the white one go? is it an earth or does it supply constant power or something? Any help would be appreciated.

Thanks wes.