Alternate Alternator Upgrade - Nissan/Infiniti

[brokencase]

The diameter of the shaft is of little consequence. I only guessed the diameter from the front images of the hitachi unit found on the web because they don't list it in any of the dimensions that I have seen.

Certainly it is not the case of..."Oh gee I can't find a pulley that works so I guess we have bag the whole idea...."

You can always make a sleeve, or bore out another pulley with a smaller hole to the right size, etc, etc...

In fact the whole art form of alternator swaps is built upon shims, washers, spacers and sleeves!

Not to mention scrounging around for long bolts...and sometimes making brackets. But we try to avoid making brackets.
...and we try our best to avoid having to hacksaw the alternator casting!

[DPDISXR4Ti]

You can always make a sleeve, or bore out another pulley with a smaller hole to the right size, etc, etc...

In fact the whole art form of alternator swaps is built upon shims, washers, spacers and sleeves!

Understood. But the less of that ^^^ required, the better.

[brokencase]

I'm surprised nobody makes these in a form to upgrade older alternators and for racing applications

https://aam-europe.contitech.de/pages/g ... fe_en.html

They are pretty cool. Let's say you rev up through 5000rpm in first gear, when the trans shifts into second, the engine rpms drop but the alternator
just continues to freewheel under its own inertia.

Increases efficiency and makes the belt last longer to.

[DPDISXR4Ti]

Now I am confused...Seems some of these alternators have the simpler 2 pin connector, which is simpler just Lamp and IGN.

Looks like the 2003-04 Pathfinder alternator is also 2-wire. I grabbed these pics from a current eBay auction.

Pathfinder2003-04Alt-1.jpg (237.17 KiB) Viewed 8393 times

Pathfinder2003-04Alt-2.jpg (223.61 KiB) Viewed 8393 times

It would appear that the Infiniti G35 and QX4 also have the same exact alternator. I had a couple spare minutes on a recent junkyard visit to look under the hoods of a couple Pathfinders and G35s. The alt is located down low on the passenger side. Access is from the wheel well and/or underneath, so that nixed it for me that day (I was on my way to a lunch meeting). All the alternators I saw looked to be original, so that points to it being a reliable unit.

[john keefe]

... this ain't my first Rodeo...

I'd say it wasn't your first either... That's a very nice, clean setup.

[brokencase]

DPDISXR4Ti - Yeah I think they are the same. Ebay list one new as 2004-06 INFINITI FITS NISSAN ARMADA TITAN 5.6 2004 PATHFINDER 4.0.
Just be sure to get the two connector type. The connectors are on ebay as well. Get the connector from the junkyard if you get the alternator that way.

Pins in connector are "S" and "L" - Sense and lamp

https://www.rotatingelectrics.co.uk/mur ... ail-pl4-wl
(scroll through the pictures)

You should only have to run the extra sense wire to the battery + and the Scorpio main wire to the stud and alt lamp wire to the other side of the connector. Although I would like to look at a Titan schematic to see how they do the ALT lamp.

I should have bought the $30 one on ebay back around December. Used ones on ebay are now going for $45.

[brokencase]

Scroll to 13:18 in this video where he talks about the alternator light and compare to Scorpio wiring diagram for alternator light.

https://www.youtube.com/watch?v=U7ZvsEW6S9M&t=2s

We have the older incandescent light bulb setup in the Scorpio. But I don't think it will pose a problem.

[brokencase]

Your pictures above are the Nissan variant, it has the curved cooling slots. The Hitachi variant has the straight slots. Otherwise I think they are the same.

[DPDISXR4Ti]

Just be sure to get the two connector type. The connectors are on ebay as well. Get the connector from the junkyard if you get the alternator that way.

For sure. That's one of the reasons I like shopping at the junkyard for this sort of stuff - the related "extras" come along for free.

[DPDISXR4Ti]

Your pictures above are the Nissan variant, it has the curved cooling slots. The Hitachi variant has the straight slots. Otherwise I think they are the same.

Any thoughts on whether one is "better"?

[brokencase]

Well - I'm not sure of the amps output of that alternator.

Anyhow...here is the alternator wiring for the nissan 2 pin connector case...

It should be no problem with the Scorpio. On the L connection the Scorpio has the dash lamp and a couple of relays that get activated as the alternator field becomes energized. On the Nissan they just have a diode, a resistor, and a battery meter. All that matters is that some small amount of "seed current" is provided into the field winding. Once the alternator starts spinning the L connection goes high and the lamp goes out.

One important point. The big wire to the battery should have a big 130 amp fusible link. More importantly, what gauge wire does the Scorpio have now? Might be smart to find out what it is and upgrade it accordingly to handle the potential higher output of the 130 amp alternator.

They also have a 10 amp fuse on the sense wire to the battery.

So to summarize...
1) Right now you have two wires to the stock Bosch alternator. One big wire to the battery and one small wire to dash lamp.
2) Big wire goes to big stud on Titan alternator - you might want to upgrade this wire to handle 130 amps and put a fusible link in place.
3) Lamp wire goes to lamp side of the small two terminal connector.
4) You run a second 14-16 gauge wire from the battery positive and connect this to the S side of the two pin connector. On this wire it is advised to put an inline 10 amp fuse.
5) For God's sake don't confuse the "S" and "L" connections! If unsure - stop and figure it out. If your lucky and get the connector with the alternator, the colors will match the ones in the diagram Yellow/Black is Sense and Brown/Yellow is Lamp.
6) Naturally, the ground connection is the case of the alternator to the mount on the engine, AND you should have a ground strap from engine to chassis. If in doubt you can always run your own ground strap to the stud hole on the back of the alternator.

[DPDISXR4Ti]

Thanks for the additional details and schematic. Agreed that any modern alternator should be wired up with a fuse. Ford used dual-line fusible links on the 3G alternator in the 90's; later on a 175A Mega fuse was used.

Looking at some more of the Nissan/Infiniti alternators, it appears that maybe the higher-amperage units are the ones that are 3-wire. As an example, look at the 2006-08 Infiniti M35 alternator - it's 150A and is 3-wire.

[brokencase]

Yea, but the Scorpio schematic does not show a fuseable link on the big wire.
Might be possible to pull the big wire & fusabile link from the donor at the bone yard?

But if the gauge of wire in the Scorpio is adequete, just use it.

It's harder to adapt the three wire. 130 amps should be plenty. I think that is what the Explorers are running from the 3g unit.
Power has always been solid on my Sport trac. I think its original battery lasted 8 years (which was pretty amazing)

[brokencase]

Just as I thought....

https://m.roadkillcustoms.com/alternato ... uge-chart/

So from that chart you might have to go from a 6 gauge to a 2 gauge wire.

[brokencase]

Cable on ebay, about $1.25 a foot for 4 gauge.

https://www.ebay.com/itm/Rubber-Flex-Ba ... ctupt=true

But this info below is in his ad...So it looks like 4 gauge should do the job.
Need to check the diameter of the wire on the Scorpio to see if you need to change.

If you change - no need to totally rip out the old wire. Just cut it back at both the battery and at the alternator and then just
run the new wire. Tape or wire tie it along the old wire. You'll probably have to use the propane torch to solder copper lugs on each end of the new wire.

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Here are the dimensions of our Rubber Flex Battery / Welding Cables:

Gauge Stranding Outside Diameter Weight per foot LBS
6 260 .303 in .109
4 364 .311 in .145
2 624 .413 in .235

SAE J-378 Table of Allowable Amperage for conductors 50V or less with 105C rating
Gauge | Amps Outside of Engine Space | Amps Inside of Engine Space
6 120 102
4 160 136
2 180 153