Restoring 1944 BN Farmall Tractor. Originally pos or neg ground?
Mustang Girl is almost there. It probably is 6 Volt, positive ground. If it has a battery, you will know if 6 or 12 volt. if not, look for a ballast resistor on the firewall. That would be in-line between the starter solenoid and the ignition switch or coil, to reduce voltage if changed to 12 volt negative ground.