bubz and sebo thanks for your replys. Been doing a little more research on the center tap winding. Looks like it used for balancing between the two halves. the mismatch of the two coils flows through the center tap trying to equalise the two. The coil with out any dot orientation is usually wound the opposite way. (opposing) Sometimes it is used to reduce magnetic hum in components. thats probably. one of the reasons the amp restricting coil is on there is to bring that part of the system back in to phase with the secondary biffilar coils. From some of the other research the center tap could be reconnected back to the other center tap windings to bring that part of the system back in to phase with the wye windings of the alternator. It sound logical but havent tried it though. just have to try to figure why the diodes are placed like that.
