SteveJ

That would indicate a failed diode to me. Wouldn't you agree, @Captain Obvious ?

The two ways a diode can fail: Open or Closed. Open: Detection - You will see infinite resistance (OL) no matter what orientation you use with your meter leads. (Always try both directions.) Result - The alternator won't charge. Closed: Detection - You will see zero (0) resistance no matter what orientation you use with your meter leads. (Always try both directions.) Result - The alternator will charge, and the car will probably try to keep running with the key off since this will backfeed the ignition circuit.

Try swapping the leads around where you got the open line. Diodes will block a resistance reading on a meter if you have the leads reversed.

I have seen the diode fail open in that design before. That would keep the car from charging. Also, if the ignition fuse in the fuse box is blown, it won't charge. The test I asked @Zedyone_kenobi to perform would help to identify those problems.

The problem is that I don't see the results of the tests I suggested you do.

There is no lamp on a 71. On the original 71 alternator, it would be a field wire and alternator neutral on the T plug going to the external VR. Since the car is modified, the field wire is jumpered to the ignition wire, and the neutral wire is jumpered to the battery wire.

The signal wire should have battery voltage. The ignition wire should have no voltage with the key in OFF, and it should have battery voltage with the key in ON.

12.3 volts while running tells me that there is a problem. However, diagnosis is not complete. Have you verified the signals for the sense and ignition inputs? Those are the two wires going to the T plug on the back of the alternator.

There are times to be pedantic. This isn't one.

Black/yellow - 12VDC switched from key in START. Black/white - 12VDC switched from ignition relay. The ignition relay coil is energized by the key in ON.

Another great share, Alan. I caught a glimpse of the link to the article on Facebook, but I didn't have the time to click on it then. I know there are plenty of us who appreciate the chance to understand what was different in other markets and why. Thank you @JDMjunkies.ch for making the time to write the article.

That reminds me of a joke. What do you call someone who speaks two languages? Bilingual What do you call someone who speaks several languages? Polygot What do you call someone who speaks one language? American

You can reach out to them on Facebook: https://www.facebook.com/s30.world

@HS30-H Alan, I wasn't looking for diplomacy. I prefer accurate. I've been reading your posts long enough that as I read through the link, I thought there was something fishy about it. The first thing was that the pricing didn't seem to fit what I recalled hearing about the 432 or 432-R market.

A friend sent me a link to this 432 for sale. https://www.beforward.jp/nissan/fairlady-z/bx082542/id/10304275/ I would appreciate @kats and @HS30-H commenting on this one. I'm surprised at how few photos and most of poor quality for a 432. Does it look like a legitimate 432? Is this where the market is on 432s now?