When I was restoring my bird I ordered new wiring harnesses from year one and I specified that I wanted it for int. reg. instead of external and all's it really was is new wiring with that plug on it.Because if I ever was to have charging problem's I did'nt want the guess work of trying to figure out if it was the reg. or the alt?Also when I bought my alt. I bought one with a lifetine guarantee from a reputable auto part's store.