alternator wiring

Hi I just put a new alternator in my 76 blazer when i converted to serpintine belt setup. The new alternator has 4 pins in it and the Bat. terminal. Does anyone know what the pins ore for? I know the big pin is for the gauge, but there are three smaller pins. thanks

I have built a 350 with the complete elderbrock performer kit and took a complete serpentine setup off a 4.3. The alt guy told me to leave the connectot unhooked and just use the stud on the rear of the alt. Worked fine for me as I used a aftermarket gauge package and used that stud to hook my gauge up to. When I received the alt It had heavy grease packed in the connector in case it wasn't to be used.