Just give me $10 and I can help you figure it out. ; )

The flow switch should be a micro switch with either an open circuit or closed circuit. A replacement phone style jack should be available from Home Depot, Radio Shack, Lowes... and yes, you will need to figure out which wires are used.

If you take the wires from the power supply, take one set of wires and short them together until you see the flow indicator status show that the flow is good. Those are the two wires used to determine flow. You should be able to use a multimeter (on continuity or ohm) to determine the open and closed circuit on the flow switch (and should be done with the power off and the flow switch removed - move the flow switch paddle by hand).

Hope this helps,