I have a 2002 350 rancher. I picked it up from my dad and when i turned the key on nothing happened. I loaded it up,brought it home to find that the 30 amp main fuse was blown. I took the spare, put it in turned the key on and everything came on. I turned it off and went back to put the top back on the fuse panel and it smelled like something was burning. I turned the key on and nothing happened i checked the fuse and it was blown again. Now when u go to put a new fuse in, it sparks bad and will melt the ends of the fuse. I disconnected the starter and it still did it. I then followed the red wire out of the bottom of the fuse panel to where it ran to the brain box. I unplugged it and tried to put another fuse in and it did the same thing. I then unplugged the rectifier and was able to put the fuse in. The only other thing that i did was to take the rectifier off of the frame. I could then plug the rectifier back up while not hooked to the frame and not blow a fuse but the rectifier would get extremely hot real quick. How do u check a rectifier to see if it is good. I believe that is my problem but any input would be greatly appreciated. THANKS

 

Welcome to the forum.

The regulator/rectifier can occasionally fail and create a key-off draw. On my Foreman the service manual suggests unhooking the regulator/rectifier as one of the steps when tracking down a key off draw.

From what you described, I think you have determined that is your problem.