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.

BONNY95, What did the dealer charge you to flash the chip, and did you drop it off, or did they do it while you waited? I asked in one of my earlier posts (aug23) about any upgrades in chipsets, sounds like their might be. Good investigation work, and thanks for the link to Alternatorparts.com, that would be some very useful info to post in the Techinfo (Moderators )

The GM dealer charged $60. My junkyard PCM was $45.

I don't recall the name, but someone told me that you can get some PCMs through "chain-store" parts places that come pre-programmed. I think that O Reiley'* price was $120 for a new PCM but I don't know if it is pre-programmed.

They said that they needed my car with the original PCM, and the replacement PCM. I just dropped the car off before work and used their free shuttle service.

I have been reluctant to go to the dealer in the past but Karl Cheverolet in Ankeny, IA has recently started offering 24 hr / 7 day a week service hours. They don't require appointments and they have always given same day service. I have been very happy with the service and their employess, and the price has not been too bad (although I still try to get the job done myself if I can).