Was hauling wagon, stopped, and it wouldn't restart, was totally dead. Put in a new key switch, it started 4 times, and the next day it would not start. Fuse (15 amp) to solenoid is okay, but gets extremely hot, it actually melted plastic casing. Battery is good, can jump start motor through coil, but then quits after a few seconds. Any suggestions? Am I looking for a short in the system, or could it be in the key switch?