Can a 6 volt positive ground generator be used in a 12 volt negative ground system? The question pertains to converting a 6 volt positive ground automobile to a 12 volt negative ground system. The majority of online automotive forums state that the field coils must be changed when converting to 12 volts. My understanding of a DC generator is that it will continue to increase voltage output until regulated, either by a voltage regulator or by the battery. So I would think only the voltage regulator would have to be changed when converting to a 12 volt system. The field coils will reverse polarity when polarized on the first connection of the 12 volt battery correct?