Current draw traced to fusible link

[Humbug]

Replaced the VR and was getting 14.5 volts to the battery.
Noticed smoke coming from the VR. Didn't remove it to see the exact source.
I do get 12V to the stem of the T connection on the wire going to the alternator, with the key on.
I'm thinking I should remove the alternator and have it checked at Autozone, where I purchased it.Another option is to just buy the ZX alternator and install it. However, the problem may not be related to either the alternator or VR.
Does anyone have some sage advice for me?
Thanks,
Joe

[Zed Head]

If you got 14.5 volts then the alternator was working.  With an external regulator you can get up to 15 volts.

I'd check the wires to the VR for short circuits to ground.  Where did you get the VR?  What brand is it?

[Humbug]

I bought it on Amazon. Brand is Standard Motor Products, made in USA. What range in ohms should I set on my multimeter to check for a short circuit?

[Zed Head]

Actually, if you had smoke I'd just take a good hard look at the wires and the connector, and the VR itself.  Something should be brown and/or warped.

[Captain Obvious]

4 hours ago, Humbug said:

Does anyone have some sage advice for me?

My (hopefully sage) advice would be to start with the small, simple, obvious.

Take a pic of the back of your alternator and post it here so we can confirm that you have the right alternator. Start there.

[Zed Head]

Another thought- make sure that the actual charging wire, the thick one that connects to B+ is intact.  The fusible link is one of the four in the two blocks up by the battery.  Check that black link.  Might be that the alternator is charging but there's no way for the charge to get to the battery and it's taking an alternate path.  Not sure how that would work, just a random thought.

Also make sure that the main ground cable is firmly connected at the starter bolt.  And that the black wire is connected to E at the alternator.  Might be that the problem is actually a ground path problem.

Looks like Nissan has it labeled "A" not B+.  You can see E also.

 

[Humbug]

Today, I cleaned the connections to the starter, put the VR back in, and everything seems to work ok. Getting 4.3 volts to the battery.

Maybe a bad connection there was the problem all along.

Thanks for Zed Head for the suggestion.

Tomorrow, I'll check for current draw. Hopefully, it no longer exists.

I'd have been really lost without the advice of you guys. Thanks for sharing your knowledge.

Joe

 

[Patcon]

14.3?

I assume

[Humbug]

Yeah, 14.3

[dutchzcarguy]

On 9/23/2021 at 2:17 AM, Humbug said:

Tomorrow, I'll check for current draw. Hopefully, it no longer exists.

I think it's sometimes wise to check a good working system, then you get some experience with electricity, especially when your not much of a electricien.. Get yourself one of those clamp-ampèremeters, they are so handy, you don't need to open the circuit just clamp them on the cable you want to know the ampèrage from!

I fear that your systems seems to work again but the problem will come back.. (if you did'nt find the culprit..) keep (at least) one eye on it...

[Humbug]

Good advice. Thanks. 

[Zed Head]

On 9/13/2021 at 4:20 PM, Humbug said:

It started around the time I replaced the alternator with a new one from Autozone.

Just a last thought - has it been confirmed that you got an externally regulated alternator?  I can't remember what happens if you try to use an internally regulated alternator with an external regulator.  I know the system doesn't work right though.

Anyway, maybe it's all good now.  There is a relay on the 76 that can cause a draw, if you still have a problem and decide to go with the internal conversion.