Never attach a power source to your motorcycle unles you are certain the electrical grounds and connections are corrosion free and verified with a multimeter to have ZERO resistance!
I Always check the electrical system first, it would be a real shame to damage your regulator, lights, starter and charging system because you assumed corrosion or damaged wires couldn't happen to your find.
Ironhead Sportster
Harley Davidson Sportster
1973 Sportster XLH
Vintage Motorcycle Restoration