Ground polarity can be switched, but you'll need to do a couple of things in the process- - - -repolarize the generator by momentarily connecting a jumper wire from the "BAT" terminal on the regulator to the "ARM" terminal, (1/2 second or so- - - -you'll get a big flash, which is normal) and reverse the wires on the coil primary terminals. You might need to swap the wires on the back of the ammeter to make it read "Charge/Discharge" correctly. Voltage regulators will sometimes, but not always give problems when running in reverse polarity. Starter, heater, and electric windshield wiper motors usually don't care which polarity they get. I believe the old vacuum tube AM radios were polarity sensitive- - - -modern solid state ones definitrely are!
Jerry
