100 AMP alternator Q&A

I'm assuming the reason you want to upgrade your alternator is because you have high electrical loads and probably lights dimming at idle.

If I were you, I would stick with a 3-wire style alternator. I used a delco 12si, made my own bracket, and bought a resistor and diode at radio shack to put in the charging light wire to simulate the light (which is then hooked to keyed power) and hooked the other wire up to the battery + stud on the starter relay (same place as the charge wire goes...I know that doesn't make sense because both the charge output and sense wire are hooked to the same place, but trust me it works better this way).

You also need 10 ga or larger charge wire.

My car has only a 78a 12SI and the volt gauge is rock solid at any rpm and with all items turned on....and its an Advance Auto Parts reman that was $55