internally regulated alt ground question.

[bananahamuck]

Needed an alternator for our 1983 280zxt ,,,,alternator i just bought was from 1984 maxima as the 83ZX in yards alternator had a weird squeek and we were already there at the junkyard...

 

Question.....  is the black plug (that wasn't plugged into car) a needed ground ?? Or extra ??The one diagram i found seem to show a plug type ground but i didn't really want to just ground it and hope for the best.. The 83 just screws into housing and doesn't have this extra plug..

 

I think this is probably a yes or no answer but i'm just being safe as i couldn't find a picture of alternator with this plug on it..

 

 

Pictures ..

 

 

 

 

 

 

Diagram i found but not sure if it applies as the E is a different spot on housing (upper right like normal)

 

[metalmonkey47]

I forgot what it's for. 'Field' I think is what my info shows at work. Output is somewhere around 6-8V IIRC so just don't hook it up to anything. It's not a ground. 

[datzenmike]

If this was a ground it would not need a plastic insulator. It would just be a lug bolted to the case. I would leave this alone (for now) and run a dedicated ground from the case (E) to the block or head where the battery ground is.

[ggzilla]

I agree - leave it unconnected. Use E for earth/ground.

[bananahamuck]

  You know i posted this ,, went and made a snack to eat,, caught a re-run of Monk and you guys come through once again..  The insulation is what had me wondering/ worrying ,,, good thing i asked.

 

 

 

Thanks you guys ..

[Dawa]

alternators ground to the block via metal to metal contact i thought? 

and if one wanted 'more' ground, they could run another ground wire?

[datzenmike]

Yes they are grounded through the mounting bolts but with any car, even more importantly an EFI car it never hurts to have a dedicated ground lug. Dizzys are also grounded through the mount but it never hurts to have an extra..

[ggzilla]

Amen to that

[DanielC]

The alternator needs a dedicated ground wire to the frame of the alternator, and to the battery.  I would think there is also a dedicated ground wire from the alternator frame to the body sheet metal of the car.   Older Datsuns used a second wire from the alternator frame to one of the bolts holding the voltage regulator.

[bananahamuck]

Yes i have a couple grounds hooked to alternator E terminal but the black plug had me confused. 

  When Punkin210 and Qtip motor swapped his 83 Maxima there was the tiniest black wire hooked to the intake that kept car from starting,, he stripped it back grounded it and car imediately fired up. You would have never thought such a tiny wire would have such a huge effect on running..  On our ZXT it seems the only thing that outnumbers vacuum hoses is ground wires..

[datzenmike]

Probably EFI related. Lots of engine sensors that work on very low voltages referenced to the grounded block or body.

 

 

The alternator needs a dedicated ground wire to the frame of the alternator, and to the battery.  I would think there is also a dedicated ground wire from the alternator frame to the body sheet metal of the car.   Older Datsuns used a second wire from the alternator frame to one of the bolts holding the voltage regulator.

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Daniel... yes. I think that black ground wire usually on the alternator is into the main harness and either to the regulator bolt or another body sheet metal connection.