Hey! just an update for those that are converting to an external voltage regulator.It is rather easy .BUT. most of the videos miss one rather important point.
You must remove the wires that go into the PCM(Power Control Module).On my 1993 D250.It was #20 Green an #61Green w/orange tracer.If not you will Let the smoke out of both the PCM an the voltage regulator.You also must use a good Regulator.My alternator shop.sold me one with an adjustment.Yeah too cool I set it @ 14.0.Ran it from Central FL. to GA.yesterday.
Hope this helps.