Voltage Regulator question, '68 DeVille

[joeinbcs]

Howdy,
Trying to run down some charging issues with my car.
It had an apparently new alternator when it arrived, but the GEN light was on and it was not charging the battery.  I took the alternator in and it failed testing at the auto parts store.  I bought an Optima replacement.  I was in a hurry and didn't ask them to check it and also didn't read the pretty bad reviews.  Installed it and there was still no charging.  Suspecting the Voltage Regulator, I removed the cap and it looks like new.  I wanted to clean the two points.  One was so tight I could barely slide one thickness of 2000 grit paper in.  The other had a little more spacing.  My question is, should I increase the gap in the tight one?  Are the points like plugs that need a specific gap?  There's a little knob on the tight one that can increase the gap.  Thanks for any guidance.  I did replace the Voltage Regulator with a new on but that didn't help either, so I'm thinking I must have got a bad alternator.  Thanks Joe

[TJ Hopland]

Are you sure you are dealing with the correct external regulator alternators and that someone hasn't swapped for a internal 3 wire or even a 1 wire at some point?  I have run into that a few times.   The cases between the 2 styles look more or less the same and will bolt in fine.   Difference is on the externals the small connector sticks out the back and on the internal regulator ones it sticks out the side. 

May be worth the time to get a diagram and trace out the wires and make sure they have not been altered somewhere.  IIRC you often would just install jumpers at the regulator end to convert but you could make it work by splicing the wires anywhere along the way.

I don't remember how they did it on the externals but on the internals the gen light gets power from a fused key on source that usually shares with other things.  If that fuse has blown it will never tell the regulator to turn on so you will never get a charge. Some of the other things on that circuit will still sort of work because they are being backfed by the regulator via the gen light so you may not notice the other things not working.   I assume the externals worked similarly.