I believe that I have my problem fixed. I installed a PCM from a junkyard 1995 supercharged Buick Riviera. I paid a GM dealer to program the flash. So far I have had no problems for several days. The problem immediately prior to this was frequent. I am hoping that this is the absolute fix. By the way...this PCM was a Delphi refurbished unit - I wonder if there are updates?
I would point out that it is a bad idea to apply 12V via battery or other source directly to the alternator "L" terminal. This may make the alternator charge for awhile as it did in my case, but I am quite confident (especially after alternator #2) that this will damage the regulator. I had read that some regulators need to see 35 ohm load to work...see www.alternatorparts.com
for more info. I wish I had read this before I tried this. I would also point out that one should refer to a specific application as there are differences in how the wiring is configured pertaining to the "L" terminal feed. Some models have the feed that is associated with the gauge and idiot light system and there are some recommendations I found to check this. For my application, this is different as may be the case for others...just look at the wiring diagrams before going on a wild goose chase.
Good luck to anyone else with similar problems, I can relate to the frustration and uneasy fealing in tracking this down. I give many thanks to this forum for the help.