Voltage issue

You didn't say what you're working on. If its a later model, and mostly stock,
First there was a small ceramic box mounted with the coil that controller the electric heat assist at choke. Those go bad a reek havoc on charging systems. Then there is a white harness connector in the engine harness that has the alt' field wires routed through it. Those are also prone to bad connections. None of the above applies to earlier models.