Here are the facts...I have a Ford 631 6V. It has been sitting a while. Took battery off (don't know if it was positive or negative ground....did not pay attention when battery was disconnected and 6v solar charger was installed a year ago ). Went to charge battery last week and neg was positive and positive was negative on battery ( did I hook up solar backwards and that caused the polarity to change over a year? Don't know). I think I remember when I got tractor that it was negative ground. I purchased new battery and have it installed as negative ground. Starts up just fine. Nothing is showing up on amp meter. All looks original on tractor. Questions ... Voltage Regulator was positive ground when original correct?...Generator, if original, positive ground correct?... Will tractor start and run ,if my assumptions are correct about positive ground of regulator and generator and if I install battery as negative ground?...Hope all this makes sense...Thanks in advance