Where do the 2 wires go from the alternator in a 1995 Buick LeSabre?

A 95 LeSabre, with the factory alternator, would typically have one larger wire to the back of the unit, then a regulator plug on the side. The large wire is the battery connection, and is usually connected, using a fusible link, to the battery connection at the starter. The regulator connection I couldn't say for sure without the wiring diagram for the vehicle, but usually one wire always has voltage, and the other has voltage when the ignition key is turned on.