I purchased an electric conversion from Brothers for my '53 GMC six volt positive ground. The installation schematic specifies the motor be terminated at the positive terminal. I contacted Brothers about running the motor connected to the negative terminal and their response was they didn't know and I should contact an electrician. That wasn't much help so I briefly ran the motor both ways, with a positive and then negative connection. Somewhat surprising, the motor rotated the same direction. I thought it would possibly reverse rotation. Not totally comfortable with this result, I contacted another vintage truck parts supplier, that offered the same conversion motor (at least the picture looked the same). They were much more responsive. The tech didn't know the answer but he did contact their supplier. Their techs weren't sure either but didn't think the polarity of the power supply would matter. I still have some apprehension about running with negative power supply if there are some internal control components that require positive power.
So, my question is, has anyone installed this conversion with negative power to the motor and not experience problems?
