Have a 1950 John Deere model A that I bought from my Grandpa. I am trying to hook the generator for the first time in ages. My dad said he was too cheap to buy a battery so they always parked it on a hill. So I have the wiring hooked up as shown in my I and T manual and when I connect the negative battery cable (positive ground) it sparks and I can hear it making a humming sound from the negative battery post and smells like something is slightly burning. The battery is a good one (started it all last winter and this summer no problems). Also, I am not hooking up lights to it nor have a key. I am kind of lost on what to do. Not sure what I am doing wrong or if that means my regulator is bad or what that even means. I don't think it should do that. Any help would be great. Posted some pictures of what I have, hope it helps. TIA!