I'm hauled for the winter, and my number one priority is to get the depth sounder and the knot meter working again. All the parts appear to be in place, but the PO cut the wiring to the through hulls right where the wiring enters the through hulls. The through hulls appear to be filled with a wax like substance designed to keep water out. Can I dig this stuff out to get at the connections? Is it wise to do so? Can it be replaced?