On the back of an alternator for a 69 Mach 1 351W there are 5 posts. Batt, Field, Ground, Sta and one that is unidentified. On a car with no factory Tach, which posts should have wires connected to them? Mine has nothing going to Sta. Also, with the key in the on position, should there be 12 volts at the Field connection of the plug that goes to the Voltage regulator? Is this to stimulate the field so the alternator will begin to charge? My problem is I'm not charging and have changed the regulator and alternator. There are no obvious broken or loose wires. This very simple charging system has me confused and frustrated.