In Reply to: 6 volt positive ground? posted by James Mort on May 16, 2018 at 14:28:08:
The original system was 6 volt positive ground. The 12 volt battery is always dead because a 6 volt system will not charge a 12 volt battery.
Making it original and reliable will require a 6 volt battery, probably a voltage regulator, and completely going thru the electrical system. I would rework, or replace the wiring harness, shine every terminal screw connection point, replace terminal hardware with new zinc-plated nuts. Look at battery cables. Toss them if they are the skinny automotive type. Replace with the proper heavy gauge tractor battery cable and ground strap. Some references list #2 gauge for the tractor battery cable. I use 1/0 or 2/0 welding cable, with brass solder terminal ends.