The original voltage regulator only has 3 wires, this one has 4. I can't find the schematic. They also used a ring lug which is too small for the relay and I had to cut it off and attach a larger lug to fit. Now it has been altered so I cannot return it. This part does not match the description, so be careful! Update: I managed to get it working. I checked the voltage with a red wire to the magneto, yellow to the alternator and black to ground, the battery was 14.6 volts. The black spade isβ¦