The main difference between a one-wire and an OEM is the method used to energize (turn on) the alternator. An alternator using the OEM style is turned on with the ignition switch, but the one-wire design is energized with a special sensing cicuit built into the internal voltage regulator. This circuit senses the rotation of the alternator's rotor. The rotor must turn at a sufficient speed to trip the circuit, which starts the charging process. The turn-on speed is affected by several things, such as pulley ratio, and may be higher on some high amp alternators. However once the circuit is tripped the alternator will charge at all speeds, even very low ones, until the motor comes to a complete stop. At that point, the circuit will shut off until the process is repeated. In short, the engine must be revved to 1400 RPM each time you start the motor, which turns the alternator on and starts the charging process. Problem solved...
Some one-wire Powermaster alternators (Part # 17127, 17294, 37294, 47294, 8002, 58005) can be hooked up as a three-wire, providing the vehicle is equipped with the two spade GM or aftermarket wiring harness. The Powermaster alternator should have a black plug cover on the side of the alternator. This can be removed and the GM or aftermarket two-spade wiring harness can be plugged in for three-wire operation. Look for the instruction sheet that came with the alternator for more details.
