Suggest you find out the model number of your alternator and find a schematic for it to be sure how it works.

Doesn't look like my 1986 RX-7 alternator.  Blurry schematic from Haynes Mazda RX-7 1987 thru 91 manual for mine attached.
Other than the B+ terminal (A-03 in schematic), it only has two faston terminals in a T. The vertical of the T (lower A-02 in schematic) is the direct connection to the built-in voltage regulator and field winding. The horizontal (upper A-02 in schematic) is the supply to the voltage regulator via a diode, which I believe is used to get the alternator going. Once the alternator is running, its voltage regulator and the field winding is supplied via the three small rectifier diodes from the three output windings. It's possible to disconnect the three small diodes to regulator/field winding and instead supply its voltage using the vertical (lower A-02 in schematic) faston connector, thus being able to turn on and shut down the alternator externally.

BTW, when engine is not running, my alternator consumes 3.45 amps to the field winding/voltage regulator, in the way I have it connected, so I need to add a "run" relay in series with the alternator field breaker controlled by oil pressure switch or I'll be heating up the field winding (and voltage regulator output transistor) with 42 watts when engine not running and master (main bus) switch on. I though it was less but measured it again yesterday.

Finn

On 9/11/2023 10:49 PM, David COOK hoursaway1@comcast.net wrote: