I replaced the Lucas generator on my welder with an old alternator from a Toyota Yaris. It worked for a little bit but the Toyota internal regulator failed.
This alternator charges the battery and is different from the 250 amp alternator that provides the welding current. Since I had the brand new regulator from the Ford alternator I decided to see if I could make it work with the Toyota unit.
It did! The finished unit is pictured above and here’s a little video on how I figured it out.