You've most likely got a short between the positive wire and the ground wire inside the windlass housing. Take off the rear windlass cover (where the manual button switches are) by unscrewing the two bolts holding it on. Then inspect the wires and you will probably find some corrosion on the connectors allowing the short. Remove all the wires from the connector(s), clean everything up and reassemble.
Test by having your crew go barefoot and wet and grab the shrouds so you don't get hurt.
Craig - SN68 Sangaris, Tropic Isle Harbor, FL