Re: Electrical System Frustration

Posted by HH56 On 2017/8/3 21:23:48

Unless there is evidence of damaged wiring or a bad connection I suspect the generator and not the wiring is the problem. It might be worth popping the band over the commutator end off and check the brushes. They might have been marginal when the bench test was done but if they have worn shorter or something happened to a spring one might not be making good contact with the commutator now.

One other wire to check is the ground on the generator. It goes from a screw on the generator case to a mounting screw on the left fender headlight junction terminal strip. Another wire connects at the same terminal strip screw and continues on to the regulator ground or a regulator mounting screw. If there is no ground screw and it is on a mounting screw, make sure the wire is on the side of the rubber insulator so the regulator base gets a good connection. Also make sure the connections are clean and are on bare metal, not over paint. The purpose of that ground is to ensure the regulator and generator are seeing exactly the same ground potential.

The regulator controls by connecting the field to ground thru some resistors. Without the wire, if something happened to the ground and the two pieces are at different potentials due to a rusty bolt or poor connection thru a bracket, the regulator wouldn't know the true value the generator was putting out. That could result in an over or under voltage condition.