fuel pump wiring?????

[turbo minivan]

ok, on an 89 caravans fuel pump and fuel level sender there are 5 wires in total. 2 wires come off the pump to a square clip ( 1 grey & 1 green with a black stripe), the 2 other wires coming from the same clip go to the fuel level sender (1 grey with black strip & 1 blue with black stripe) now, im guessing these wires ive mentiond are just positives and grounds. now heres the guestion, the fuel level sender plug has 3 wires coming from it, 2 go to the square clip like i mentiond, the 3rd one goes to a clip all of its own, i need to know what this wire is. is it a ground, is it to the gauge? help!