The alternator converts mechanical energy from motor to electrical energy. A Starter converts electrical energy from Battery to mechanical energy to spin gear that engages with the flywheel. The Datsun 240z 260z 280z from 1969 to 1977 used an external voltage regulator, mounted to the passenger fender above the frame rail. There were 4 different models of Alternators. Datsun improved the alternators to produce more current to meet higher demands. The Rotor rotates in the Stator, there are 3 different field windings, producing 3 phase AC current. The current is cleaned up and converted to DC by 3 sets of diodes. The voltage regulator is connected at the T-shaped Terminal. Circuit “F” Field circuit with a White/Black wire and Circuit “N” Neutral Point Voltage circuit with a Yellow wire. The Alternator output “A” Circuit is the White/Red 8ga wire connected to Battery. The Voltage Regulator 12V feed from the fuse box/battery is the voltage input, this is the white wire in the 6P connector from the wiring harness. The Black wires are ground.
Below is a table showing the Data and Specifications from the Factory Service Manuals from Nissan Motor Corp. All images and data are from the Factory Service Manuals