I just bought a friend of mine's boat that I had been out on it a hundred times. It has a 24 volt bow mount Minn kota Maxxum 70 or 74 lb thrust 42" shaft. I took it out today and half way through the trip the motor would not shut off. I finally had to disconnect the positive cable. It would not work after that. I opened the top when I got home and found that a couple of the wires had melted at the connectors.(The unit had a circuit breaker on it). I replaced them put it back together and it worked but only had 1 speed and again would not shut off. Any help would be greatly appriecated.