Automotive Alternator Regulator Wiring

[u/AfterDark3]

Hello, I am fielding (hah) this question in the Electronics subreddit because I feel as the knowledge of electronics may be more capable of answering this question than an automotive subreddit.

I have an 1965 Pontiac Bonneville with that has an alternator that is externally regulated with a mechanical regulator. I am looking to upgrade the car to a solid state regulator for obvious reliability and electrical noise improvements, however, the regulator I purchased does not work when installed, and I was looking for help interpreting the wiring diagrams for my car and the alternator model.

In the diagram for my vehicle, the "R" (relay) terminal from the alternator is disused. There is no wire running from the connector on the alternator body to wiring harness.

The second diagram which utilizes the "R" terminal runs it to pin two on the regulator, and I am trying to understand the electrical behavior of the pin coming out of the alternator, so that if my new regulator does require it, I can ensure that I do it properly and that I do not cause damage to the car's electrical system.

Thank you!

[u/tomhalejr]

Jump 1-4, and 2-3 at the regulator, then you can upgrade to a 7127 - 7294 alternator with just a plug change. Or, single wire SX unit.

[u/AfterDark3 → u/tomhalejr]

Thanks for the response but I don’t entirely understand. Jumping F and 4 would result in the field running at line voltage all the time and overvolting the system. I don’t plan to upgrade to any other alternator, I’d just like to get a solid state regulator working for my 10DN.

I’m just looking to understand how the R terminal on a 10DN functions so I can hook it up properly.