1996 REGAL Limited Still not Charging (?) !!

I replaced the alternator a few months back because the car was just dead spots all over when you got on it. Come to find out the battery Voltage was low but no idiot light for the alternator came on . So i replaced the alternator,and i figured i needed a new battery as well so i put a RED TOP Optimas in there.. Well since then i ran Thur the whole car making sure no fuses , fuse able links, or any other breaker was blown,burned,or damage. Nothing all checked out well then i replaced the cars CPU thinking it controlled the 10.9 volts going to the the field to energize it and turn on the charging part for the alt. Any how to no avail
since that time i tired a half dozen new alternators,everything but still the alternator will not charge it will not put out more then 12.6 to 12.9 volts
Please if anyone has every had this problem, and can share or tell me if
they know whats up. so a recap 4 alternators, new car CPU, no fuses or links bad, but nothing will not charge. I have to charge this car every time i go on any kind of lengthy trip.. EVERY DAY i have to use my charger

Please Help Me Have Mercy On Me Please (!!)

THANKS & GOD BLESS

CODMYSTER