No charge at battery

A short review:

Wiring harness have voltage drop I don't care how good condition they are, unless you have taken steps to vastly over-design them. That is, the field wire, supplied by the ignition switch, WILL have "some" drop even if only a few hundredths of a volt. Bigger wire, better connections, relays will change this, sometimes a tremendous amount.

The charge path, AKA the path from the alternator output, through the bulkhead, the ammeter, back out the bullkhead, and all the terminals in between will have some drop. This is (mostly) not that serious, because the regulator will ramp up the voltage until the sensing/ ignition terminal is "satisfied" at the VR setpoint. That is nominally 14V

I wish I could be "there" for some of you, because teaching "voltage drop" is not that difficult, but it is a lot easier if two guys can "see" eye to eye.

This, still, gets back to "the path." The circuit path of the field wiring to the VR from the battery, the grounding of the VR to the battery, and whether or not the alternator is actually performing. That is, "maybe" it has a partially shorted rotor, and even though the VR is trying to send the rotor full current, the damn thing is just simply not putting out. This can usually be determined by following the manual, full output tests Bypass the VR and determine if the alternator is "able."

Bad diodes can limit output, but these also almost always cause ripple, which is easily found by monitoring with a voltmeter on AC range, or noise in the radio if equipped.

Many guys who know me know that I dislike "throwing parts" but sometimes it will fix things in desperation, and sometimes it will at least tell you that you are on the wrong track!!!