There is a tube that extends up a few inches, where the electrical wires pass. There is also a drain hole in the mast step to allow water to escape. If the drain hole is clogged then water can back up and leak into the tube where the wires are. I helped my buddy fix his by cleaning out the drain hole. I don't remember exactly where it is but I am thinking that it is forward of the mast. Use a wire to ream it out. If I remember correctly it is hard to see.
Good luck.