One Wire Alternator Conversion
What do you do when the stock alternator was originally externally regulated? It's simple! The only thing you need to hook up on a one-wire alternator is a charge wire from the terminal on the alternator to the positive terminal on the battery (or any positive battery source). The external regulator can either be totally dismantled from the firewall or left in place. If left in place, be sure to disconnect the wiring harness from the regulator. The wiring harness has to be disconnected from the regulator or the indicator light on the dash will remain on. Note: if the vehicle is equipped with an indicator light, the light will no longer be operative.
Most 1-wire alternators have a charging point set around 1200rpm or higher. This is the speed where the internal sensory circuit connects the battery voltage to the regulator, thereby turning the alternator on. Once the voltage regulator turns on, the alternator will remain on and charging until the engine comes to a complete stop. If the engine idle speed and pulley ratio combination does not allow the alternator to come to during start-up, the engine will have to increase the RPM to engage the one wire alternator. One exception to this is Tuff Stuff's heavy duty 140 amp performance alternator rated to charge 80amps at 750rpm.
Changing the pulley ratio on the alternator by slowing it down will generally keep a one-wire regulator from charging. This can also produce a low voltage problem at engine idle speed depending on the amount of reduction. Alternators are usually tested with a 3:1 pulley ratio. This is the recommended street pulley ratio and is used in most factory applications.
