Have 1995 Gregor Seahawk g4. In process of fixing fuel sending unit, or fuel gauge. 3 wires coming off top of sender. 2 black, 1 pink. One of the black ones runs from one of a mounting screw on the top of the sender to a clamp on the fuel fill hose. Anyone know what that wire is for? The other blk one goes to batt ground. Thanks in advance....Bill