Do you have a wire connected to the stud on the back of the alternator? If you are re-wiring the connector at the voltage regulator, the bigger wire usually either goes directly to the battery, or loops to the stud on the back of the alternator, which should have another wire that goes to the battery. GM used the same style connector on many applications which had anywhere from 1-4 wires, and the aftermarket replacement has 4 wires (one part number replaces all factory connectors, you just wont use all the wires on the replacement connector).