I have a failrly new optima battery, and one day it stopped charging, i bought an alternator, didn't work, so i exchanged it for another with the same outcome. next i get it checked and the alternator was fine, the battery charges with a battery charger and if fully charged in the car. i have an 87 350 tpi, the alt has a 4 - pin wireing harness. someone HELP please!

 

I think the main red wire from the alternator has a fusible link in it, run a new wire from the terminal on the back of the alt to the battery + terminal and see if it starts charging. Might need to run a new heavy duty wire if so.