That is not a one wire alt. That looks just like a standard GM alt with an internal voltage regulator. The only wire a one wire alt needs is the 12 volt output wire. The wire they tell you to hook a resister to is normaly ign voltage from the ign switch. It uses the voltage flow on a stock GM that goes thru the alt lite on the dash and a resister in parellel with the lite to exite the field when it starts. The other small terminal #2 should nbe 12 volts at all times. A one wire alt self exites the field when it starts turning and uses the alt output volts to set the internal regulator volts also. If you use it I would just hook the small wire #1 up to ign voltage and use a voltmeter in the car to monitor charging volts. If you hook the small wire # 1 to 12 volts hot you will drain the battery with the key off as it will be feeding the alt field with the key off. Or as Mr P says you could use a solenoid to kill both with the key off and then you could hook the small wire to battery volts. Ron