Blumarin, I left the voltage regulator as a dummy when I installed a 10SI alternator. I needed to install an alternator when I added A/C. I used the BAT terminal on the voltage regulator as a junction terminal for the battery connections and just don't have any wires connected to the other two terminals.
If you install a three wire alternator, this will give you a great place to attach the voltage sensing wire if you hook it up the way I did. My A/C power feed also is attached to this terminal.
Matt
