Hi - I have a V7 Sport with the early 13A alternator. It has 5 wires (3 AC, 1 hot & 1 ground to rotor). All the rectifiers I find have the 6 wires (5 plus a "Y" wire to extra diodes). What is the "Y" wire for and can I use one of these rectifiers without connecting anything to the "Y" lug on the rectifier?