The blue and red wires came from the old 4ac alternator plug. They then went into the external regulator and the outputs(technically not for ignition wire) from the regulator are the yellow lamp and black yellow ignition wire. If you strip back that loom a little you will find you can completely remove the blue and red wires and get rid of that 6pin plug (and the 3pin 4ac alternator plug if its still there ) all together.