You have an alternator to charge your battery. You can hook up your Faria tach by connecting the send wire from the tach to either yellow wire on your rectifier. Set the setting switch on the back of the tach to 12 pole/6pulse.laddies, i've got a faria tach on my '66 500 and i'm fairly sure its magneto and it works fine. everyone here told me it was magneto when i asked about how well it should charge up the battery with accessories on it. im i wrong and its an alternator?