im replacing the voltage regulator in a 1995 impreza oem alternator and have found the weirdest thing. When searching by part number from the alternator the voltage regulator that typically is shown is this 3 contact one. The one inside the alternator doesnt have the middle contact. Does anyone know why this is? And what the middle contact is even for? The 3 contact one is made in japan and is mitubishi stamped even. Im wondering if i can just use the 3 contact one anyway. But im unsure of what to do about that middle contact since there isnt really an obvious spot it solders to. I found a manufacturer that sells one identical to the one inside the alternator for a fraction of the cost. 8 dollars verses 150+. Maybe someone has some insight into this? Thanks!