I was probing the yellow wire with it plugged into the alternator with the car on. 
 

Can it damage the wiring (or anything electrical in the car) if I drive it like this until the replacement one arrives?

It's a 71 so it doesn't have any sensitive electronics.  And 15.1 is in the range of the original external regulator.  So probably not, but if it's defective it might fail even farther.  Why not put the old external system back together while you wait?

Unfortunately the old external VG was melted so I threw it out. 😞

I guess I’ll just have to wait for the replacement. If this 3rd one is defective for some reason, I might just have to pay more for a new one vs. the remanufactured one. 
 

Hopefully the new, new ones are better quality and tested more thoroughly. 

It's not uncommon.  The internet is full of bad reman alternators.  The reman shops only replace the parts that don't work, they leave the stuff that's on the edge.  I thought that Remy was a good company though.

4 minutes ago, Zed Head said:

It's not uncommon.  The internet is full of bad reman alternators.  The reman shops only replace the parts that don't work, they leave the stuff that's on the edge.  I thought that Remy was a good company though.

That is part of what drove me to do the Frontier alternator swap on the 260Z. I had a good ZX alternator that I decided to use in the 240Z when I was waking it up last year. That used up my reserve. I learned I could get a new Frontier alternator from Rockauto, so I went that route.

I would not drive it until got a good alt JIC it gets worse. On mine it was way over volting based on the brightness of the head lights. 

Third time's a charm... so the first one had a bad diode (or two or three) and caused the battery to drain.... the second one had a bad voltage regulator... and the third one finally appears to be working properly. 

 

Remy/BBB definitely has some quality assurance issues and I would highly recommend getting a "NEW" one instead of re-manufactured if you have the chance.  If I had to do it over again, I would NOT go with a re-manufactured alternator.

 

Thanks all for your help!

20 minutes ago, eastcoastz said:

Third time's a charm... so the first one had a bad diode (or two or three) and caused the battery to drain.... the second one had a bad voltage regulator... and the third one finally appears to be working properly. 

 

Remy/BBB definitely has some quality assurance issues and I would highly recommend getting a "NEW" one instead of re-manufactured if you have the chance.  If I had to do it over again, I would NOT go with a re-manufactured alternator.

 

Thanks all for your help!

Back in the day, it wasn't bad to get a reman. As I mentioned before, the one I put in the 240Z was purchased many years ago. I'm not sure what happened between then and now, though I have my guesses. A friend was having issues with his 77 trying alternators and a voltage regulator. I tried to get him to do the upgrade to the Frontier alternator from the start. He spent more his way, though. The good news is that he's been happy with the alternator swap I did.

When I replaced the alternator on my 240 it popped all my fuses as soon as I tried starting the car. Got on this wonderfully packed with knowledgeable members and found out it was back charging, whatever that is. Took it back to Advance and they gave me another reman, on a whim I asked them to test it before I left their store. It was bad too, also the last one they had. They sent a guy across the street to Autozone and got one from them, tested it and it was fine. Still fine. My lesson learned was to have them test anything re-manufactured before I leave.

After going thru this same kind of thing, I ended up just fixing my old alt, in had a shorted diode pack, replaced it (3 wires maybe 30min total job) and been running it ever since.