my old school self and my nasa electonical injuneer old school buddy tore into the original honda cubical plate rectifier just to clean it, and lo and behold there is a paper thin insulator pipe that covers the ground/mounting bolt (one and the same), which fell apart inside the unit who knows how many decades ago. the insulator keeps the hot incoming wires from going to the ground bolt, there are 3 yellow form alternator, and one red from batt?. if the insulator is bad, you WILL have a voltage drop. and one green.
THE FIX. pull out the bolt carefully, clean parts to expose fresh brass(do not take apart cube part, or remove the inside wires. remeber where everthing goes, take digital pictures. clean bolt if needed. cover the bolt with 2 or 3 coats of heat shrink insulator tubing, high enuf to cover bolt where the hot leads come in, cut off excess with razor if needed. reassemble. done deal. these things look like flash gordon parts.
