So sorry you experienced this situation. Funny how at AutoZone off-board test the alternator voltage was not abnormal. I was surprised at the wear debris art the rear armature and brush area. I feel your decision to replace the alternator with its internal regulator is reasonable, FWIW. For our 1969 GT500 and both 73 Mustangs, I opted to use first generation alternators with external regulators. The GT500 and Mach 1 both have electronic regulators. The 73 vert has only 21,000 or so original miles on it (barn stored over 40 years, literally), and its voltage regulator is the original electro-mechanical unit. Both 73 Mustang alternators have been rebuilt, whether needed or not, where I opted to swap in high amperage components (more rotor windings) in order to boost their amperage output. I figured of the higher output level is not able to keep up with the electrical loads I would go to a single wire alternator solution. So far there has been no need no move to a 3G alternator (whew), which I am glad for as the 1G units are performing perfectly well.
I any event, I am glad you shared this situation as it brought out some great suggestions. It is always nice to see folks chiming in with such great info. If nothing else it bolsters/reaffirms my outlook on many of the suggestions. That said, I personally like the 1G alternator/regulator setups, just because for the most part they work well enough for my electrical needs, and I retain the factory wiring per schematics. Less grief for whoever ends up taking the reins for these nice cars years (better yet, decades) from now. As it is I need to update the wiring schematics on both 73 Mustangs to show the dual electric fan circuitry, and other non-standard wiring (LED taillights, GPS with wireless rear backup camera), center console Power Panel., etc.
My hat is off to you and our fellow colleagues in this forum who pitched in their thoughts and suggestions.
) I submit the following tech article:
