Hi, I have a 1973 240z, rewired the car with an EZ wire harness, and I have upgraded to a 60 amp alternator from a 280zx. I've driven the car fine until I had an issue of the alternator overcharging. The original 60 amp ended up testing bad, so I replaced it, and made sure to test the new (re-manufactured ) one I got. It tested fine, but when I installed it in the car, I hooked up a multi-meter and it was going up to 15.7 even after warming the car up, and putting load on it, including lights and an electrical fuel pump. Anybody have any idea what could cause this? Such as a wire too small going into the voltage regulator, or just an alternator that instantly went bad? Or something else? Thanks for any help!