TunerMaxima3000

iTrader: (4)

1st: This story is NOT about the 5th gen, it's from my 03 G35 sedan. Because it's all the same Jazz, and this is the 2nd Nissan that has been fixed by this method, I'm sharing it with you in hopes it will solve a future problem you're having.

Now on to it.

Once upon a time, my car died. Needed a Jump (no power). Well didn't I grab another vechicle to jump & charge my battery, took some time but finally got it started.

I grabbed my trusty Multi-Meter and tested the Voltage at the battery, well wouldn't you know, no chargy! 12.2 Volts and dropping fairly quickly.

During jump-startup I heard a squeeking from the alternator pulley fairly consistantly, Because of this, I didn't bother diagnosing further, I just got an alternator.

I grab my Re-Mann alternator and jack up she 'ol Jizzy (The G's name is Jezebel, Jizzy for short, of course). Removal wasn't too aweful, so out it came, and in went the 'new' one!!

Start 'er up, Jizzy fired up with a tremendously confident purr. Running unassisted. Yah, whoo hoo, etc, you say? Nah, I grabbed that trust multi-meter again, Just to double check this thing
Charging at 16.5-17.0 volts!!!!!!!

(That's excessively overcharging, for those that didn't know, it should never put out more than 14.2-15 Volts Peak, ever.)

So I check the usual suspects, terminals, connections, and so forth. I check the FSM and it's wiring diagrams, well it's an Internal regulator, confirmed, so i remove the alternator again, and return it for a replacement (again).
It's obviously the regulator in this REMAN Alternator.

Get my new-new REMAN Alternator (same manufacture), Jack up she old Jizz-mAcHiNe again! Swap, and wouldn't you know it!!! Overcharging!~

Now I'm second guessing, right? Yup. For sure second guessing.
SO I perform every bit of troubleshooting and testing that FSM has, it all leads me to REPLACE ALTERNATOR.

Then I even go as far as to ADD grounds with jumper cables, and so forth. No change. Tried a different Multimeter, tried a different battery, etc.
After I was satisfied with my testing, I had to call this Alternator again. Must be a string of crap ones from this manufacture, right?

Go get ANOTHER REMAN from a DIFFERENT manufacturer. Install. Jizzy is just flying up and down on the jack

And here she is, OVERCHARGING still.

So I remove the alternator. I take it in and have it bench tested. I tell the Fancy "ALTERNATOR REBUILDER DUDE" the story, and have him test the one I have. He says she charges at 14.1 but he wasn't convicnecd it was o.k., he think's I'm right and these alternators are wrong/junk.

Because he got it to put out 14.1 Volts, i left with the one I had, unwilling to accept that 3 Alternators in a row all have the same issue.

Me and my replacement vechicle roll out, off to the Surplus store, and grab $60 in 4 AWG & 8 AWG wiring.

Tested ALL WIRING, all Grounds, etc. ALL TEST GOOD. Remove them anyways.
Inspect them thoroughly, THEY ARE GREAT looking, clean, etc.


REPLACE THEM ALL ANYWAYS. Add/ Install new grounds - EVERYWHERE on this Jezebel P.O.S.

Install Alternator. Charges great. 14.3 Volts peak, 13.6 Volts just chillin.

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The moral of the story? This is the second Nissan I've had that had a super strange Electrical nightmare & the final resolve was adding grounds.
The other one was a 4th gen with an intermittent no-start that would fix itself temporarily off and on, and would fix it self EVERY TIME I put a new starter on it.
The fix for that was adding a ground fromt he tranny to the Chassis, never acted up again.

There's a logical reason why this worked on this alternator, but I won't get into that, as this is literally already a novel
Just wanted to share the concept/repair for anyone who may have a starting/Charging mess like I've had here. It's something you should be doing in your diagnosis repair (Adding & Replacing grounds).

Amerikaner83

iTrader: (17)

makes sense...

Especially when using a meter to measure from ground...if the grounds are not "in sync" with each other you get irregularities.


ps - I like the name of your car I have yet to name my max

TunerMaxima3000

iTrader: (4)

There was only 1 hint through my testing that pointed towards anything remotely related to this. The BATTERY indicator lamp in the dash would operate normally even though it was overcharging.
By that I mean, it turns on when car is off, key in "ON", before starting. Then once started the light goes off.

This circuit is ground triggered via. the regulator in the alternator. So it works when the car isn't running but doesn't work when the car IS running.
At a glance though this was 'most likely' due to a bad regulator not doing it's job and triggering the overcharge lamp.

Looking back, I theorize that once the Alternator was running (Spinning/Charging), the ground path through the alternator and into the block, then back to chassis, and ultimately to the Negative terminal was too restricted to allow enough Current to pass through it.

This resulted in a lack of ground through the alternator, thusly, a lack of ground for the Regulator. Surely not enough to stop anything from working, JUST enough to interfere with the Regulator doing it's job properly, and properly sensing the Voltage Accurately enough to 'regulate' it.

But while it was OFF, there was plenty of ground path for the minimal amount of current needed.