Alternate Alternator Upgrade - Nissan/Infiniti

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brokencase
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Alternate Alternator Upgrade - Nissan/Infiniti

Post by brokencase » Mon Nov 26, 2018 8:43 pm

I'm with you Ed, the stock alternator is lousy.

So I am sticking with the clutched fan for now, but I am intrigued by the idea of the electric fan as I think it might help speed up
warm up time and increase mpg.

The Scorpio comes with a quite powerful electric fan on the A/C condenser.
In a stock Scorpio it almost never comes on, it is for when things get out of hand.

I had performed the mod to run the fan whenever the a/c clutch is activated. This gives a noticeable boost to A/C performance
in the summer time and when in stagnant traffic.

However I soon noticed the high current draw of this motor and the heavy toll it takes on the battery.
I took the fan off and measured that it draws almost 20 amps continuously. It moves a ton of air and by itself is sufficient to
replace the clutched fan.

But the Bosch alternator can not keep up with it. The alternator is supposedly rated at 90 amps, but I don't think it puts that much
out at idle or even slightly above idle

I bought and swapped in a modern aftermarket fan of the same diameter on ebay and it draws about 6 amps.
I also installed an aftermarket voltage regulator that is adjustable. It helps somewhat but is not the ultimate solution.
These changes allows my a/c mod to run fine. So I am pretty happy with this setup.

I agree some sort of modern alternator swap is in order. However the Ford 3g and 4g units don't have the proper mounts.

Take a look at the 2004ish Toyota Highlander and land Cruiser alternators over at RockAuto.. They seem like they might fit with very little work and come in 130 amp flavors.

Correction..2004 Pathfinder - See below...

Who wants to be the guinea pig?
Last edited by brokencase on Sun Dec 02, 2018 7:18 pm, edited 1 time in total.

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re: Alternate Alternator Upgrade

Post by DPDISXR4Ti » Mon Nov 26, 2018 11:28 pm

I'm not at all adverse to an alternator upgrade. Both the Brat and F-150 are upgraded to 3G units. I wouldn't mind running the same alternator on the Scorpio, but if something from a Toyota (or whatever) swaps in with less effort, that's fine too.

For reference, here's a link about using the Contour fans. They push 3400 CFM combined. The fans pull 22 amps each at start up, 9.5 amps running.
https://www.pirate4x4.com/forum/jeep-no ... fan-2.html

Sounds like the alternator upgrade would need to come first.

I need to study the hose plumbing. It's nice having a '89 parts car in the yard for comparison.
Brad

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Re: Alternate Alternator Upgrade

Post by Ed Lijewski » Tue Nov 27, 2018 8:22 am

The PITA (a YUGE one) In finding/adapting a 3G unit on the Scorpio is access to the alternator; it's a challenge just to R&R the OEM alternator (unlike on the XR/F150). Ideally one would use a removed Scorpio engine to mount up whichever 3G unit will fit.

YMMV
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Re: Alternate Alternator Upgrade

Post by brokencase » Tue Nov 27, 2018 1:55 pm

There is post in this forum somewhere, where someone put a 3G alternator in the Scorpio but they had to do serious cut and welding to make it work. Not worth the effort IMHO.

Replacing the stock alternator is not too bad from below.

We are not the only ones who do not like the Bosch 90 amp alternator. The Volvo folks of same vintage don't like them either.

You can get the adjustable replacement regulator from ebay. This guy talks endlessly about them but he is only selling things...
http://www.240turbo.com/AdjustableVoltage.html

Here is the one on ebay...
https://www.ebay.com/itm/Voltage-Regula ... ctupt=true

The adjustable regulator helps a little. I saw about a half a volt increase at idle just after installation. I put it in at the end of the summer.
Haven't had time to fully explore the adjustment range.

There is another article somewhere on the web where folks have adapted an external Ford regulator to the Bosch alternator.
This supposedly takes care of it's lazy output at low rpms, but I have not the energy to do this.

If I am going to go to that level then I would rather adapt a modern Japanese alternator. Hopefully where it is just some bolts and spacers,
a pulley swap, and some wiring lug changes.

How about 220 amps from something like this?
https://tinyurl.com/y9r45hm7

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Re: Alternate Alternator Upgrade

Post by Ed Lijewski » Tue Nov 27, 2018 6:52 pm

The only way to R&R the Scorpio alt IS from below; I've done that routine easily 6 times swapping in good used and new remanned units hoping one would maintain higher voltage levels under typical accessory loads. But it's essentially a one handed lift from below to get the unit around and above the trans fluid to radiator and PS lines and near the mounting boss (assuming the car isn't on a lift).

YMMV
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Re: Alternate Alternator Upgrade

Post by DAReese » Wed Nov 28, 2018 1:52 pm

Ohio Generator can get an alternator that works and has the output you need. They do it all the time for high-end audio installations. Probably won't be cheap though. https://www.facebook.com/pg/OHIOGEN/rev ... e_internal
David Reese

88 XR4Ti - mono white T5, someday to be bi wing
89 Scorpio - waiting on some parts before it hits the road again
88 XR4Ti - mono red C3, parts car
used to own 86 dark blue traded in on a min van, what was I thinking?

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Re: Alternate Alternator Upgrade

Post by Ed Lijewski » Wed Nov 28, 2018 5:38 pm

Screenshot_2018-11-28-16-34-26-270x480.png
Screenshot_2018-11-28-16-34-26-270x480.png (44.33 KiB) Viewed 3618 times
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Re: Alternate Alternator Upgrade

Post by Ed Lijewski » Wed Nov 28, 2018 6:14 pm

Later Euro MKIII 2.9 v6 Scorpios had alternators with higher amp rating (~120 IIRC). Maybe one of those would be a drop-in.

YMMV
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Re: Alternate Alternator Upgrade

Post by brokencase » Thu Nov 29, 2018 2:07 pm

Yes there are high output upgrade parts available for many stock alternators.
But I have found none for the Bosch 90 amp unit, at least none from any of the domestic alternator spares outfits.
Otherwise I would have done this upgrade a long time ago.

The later Euro Scorpios are multi-vee belts. And do you really want to have to ship one of those over here?

Swapping a Japanese alternator is the way to go.


Here is the stock Bosch 90 amp unit...
Image

I scoured through the images of alternators on RockAuto and I found this unit that looks to be a close fit.
It is from a 2004 Pathfinder...Available as 130 amps...

Image

Image

Visually it looks good from a mounting perspective, but I have no actual dimensions.
Also you will need to find the pinout of the Pathfinder alternator and get a connector to plug into it and adapt
accordingly. I think it might be best to find one in a junkyard to minimize the investment into the experiment.

You will have to imagineer the pulley solution as well (an you might need spacers to get the V pulley to line up right).

Also, I am not sure if the Pathfinder alternator is internally regulated, but it probably is. Most newer alternator are.

This unit probably applies to several other vehicles, just don't know the reverse lookup.

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Re: Alternate Alternator Upgrade

Post by brokencase » Thu Nov 29, 2018 8:07 pm

I still don't think he can do a high output version of the Bosch 90 amp alternator.

The high output alternators are all based on kits from the aftermarket. I have never seen one for the Bosch.

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Re: Alternate Alternator Upgrade

Post by Ed Lijewski » Thu Nov 29, 2018 8:36 pm

Not skeered of shipping an alternator from say GB to here. Shipping for two front struts and two rear shocks (~35 lbs.) via UPS cost me ~$60; a single alternator shipped wouldn't weigh more and very like less. So, yes; it if mounts on the 2.9v6 we got, it ships.

YMMV
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Re: Alternate Alternator Upgrade

Post by brokencase » Sat Dec 01, 2018 5:27 pm

You still end up having to change the pulley...and who knows what else?

IMHO, It makes sense to look for an easy Japanese alternative.

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Re: Alternate Alternator Upgrade

Post by dimswits » Mon Dec 03, 2018 5:45 pm

Ed Lijewski wrote:
Mon Nov 26, 2018 6:25 pm
Electric fans will draw amps. I've observed in both 88 and 89 fan clutched Scorpios that the electrical system just doesn't produce voltage at the battery as does the XR. On my XRs running with headlights and blower on high I consistently get voltage no lower than in mid 13s (14.4 with headlights and blower off) readings. Not so with the 88 and 89 Scorpios IME, where under the same current draws readings at idle are closer to 13.0 and occasionally a few points below that. And in each Scorpio the alternators/VRs were new remanned units, and in each the batteries were brand new and fully charged, and battery and accessory cable connections clean and in good condition.
Where was your test point for these readings?
Dimitri in NYC
88 Scorpio 2.5 Turbo
89 Scorpio 4.6 DOHC
02 E46 330Ci
17 MKC

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Re: Conversion from Clutch-based Mechanical Fan to Electric

Post by brokencase » Mon Dec 03, 2018 9:34 pm

No luck on the Ranger front, it's mounting is different than that of the Scorpio.

All that you, I, or an alternator rebuilder can do is look at the various other alternators and try to find something close - mounting wise.

I really think the Pathfinder alternator is the way to go. There is a used one up on ebay right now for $42.50 130 amp
It even has the original connectors attached. It is perfect for the experiment.

I'm just having a hard time finding a definitive wiring diagram for the three terminal connector.
I am pretty sure one is "Sense", the other is "IGN on" and the other is "ALT Lamp". I just don't know the order.

The Sense wire just goes right up to the battery plus terminal, and is separate from the big wire that goes to the same place
IGN on - switched power from ignition switch
ALT lamp - I THINK will work with the stock Scorpio lamp.

Of course there is also the big stud for the big wire that goes up to the battery.

Incidentally, the lack of a separate "sense" wire is probably a contributor to the poor performance of the Scorpio stock alternator setup.
Pretty sure most modern alternators have this. It allows the alternator regulator to monitor the voltage right at the battery independent of the loads occurring through the big wire. In other words, very little current flows through this wire, it is voltage monitoring only.

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Re: Alternate Alternator Upgrade

Post by brokencase » Mon Dec 03, 2018 10:26 pm

Here we go...I think the link below shows the right pinout. The Pathfinder is the same as the one in the middle.

http://wilbo666.pbworks.com/w/page/3944 ... lternators

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