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solid snake

how to install a 90 amp alternator

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I would highly recommend for anyone who is running a e-fan or offroad lights to upgrade their alty because this not only causes havoc with your electrical system, but the tranny can be affected as well and can lead to damage, like what happened to me pssd.

 

Tools required:

Ratchet

12 mm socket

10 mm socket

Phillips head screw driver

 

The process to install the new alternator is pretty straight foward, and a direct bolt on. First thing you want to do is look for your donor, the alternator that would fit into your 86-95 pathy would come from a 85-94 maxima. Make sure that you are getting one from SOHC maxi and not a DOHC, especially with the later year maxi's. Here's the diffrence:

 

th_dohcalty.jpg

 

th_SOHCalty.jpg

 

As you can clearly see the mounts have diffrent angles. The other between the two is that the DOHC generates 5 more amps than the SOHC.

 

This is the diffrence between a pathy alty and a maxi alty:

 

th_DSC01021.jpg

 

th_DSC01022.jpg

 

th_DSC01023.jpg

 

The maxima alty is slightly more beefier than the pathy. Ok, if you decide to get your donor alty from a J/Y, then having it tested out at autozone or checker is recommended.

 

First thing's first. Disconnect the positive lead on the battery. Unbolt the tensioner bolt with the 10 mm socket and with the 12 mm socket unbolt the bolt holding the alty in place to the tensioner to remove the belt. unbolt both the two bolts that hold the alternator to the engine block with the 12 mm socket. I would recommend to remove the back bolt first, and then remove the front bolt, while holding the alty with one hand. Once you have removed all bolts, wiggle the alty slightly to remove from block. Disconnect the pos lead to the alty with the 10 mm socket and remove the ground with the screwdriver. It the screwdriver does not help, then you may want to use a smaller socket, I think it was a 7mm, don't remember. Remove last plug in harness. Take the both alty's to a shop where they can swap the pulley for you, unless you already have air tools. Once the pullies are swapped, take the maxi alty and install all factory wiring again. Start by reinstalling all engine block mounting bolts, do not tighten yet. Install the tensioner to the alty, along with the belt. Tension the belt acocrdingly so it is nice and snug. Tighten all mounting bolts, reconnect the pos lead on the battery and start the pathy!

Here's some pics of the alty installed:

 

th_DSC01084.jpg

 

th_DSC01087.jpg

 

Over all the swap should take about 30 mins or less. I'm pretty impressed with the upgrade. The tranny problem i had started when I installed an e-fan and ended when I upgraded.

Edited by solid snake

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Stock is 70 amps. A 90 amp alternator is a 20 amp increase. Just so you know. You can also swap pulleys yourself if you have a v-belt strap wrench like I have from Harbor Freight. Good write-up!

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Thanks! i forgot to mention that. Stock pathy amperage is 70. I didn't have a v-belt strap, so I just walked down to the mechanic shop down the street form me to get the pully swapped, no charge at all :aok:

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Pulled the alty out of mine last week in anticapation of getting my new Maxima alty, mine was actually a 60 amp! :(

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What year was it from. Cause I checked all the years up to 94 on the alty. I cheked autozone and checkers and since they replace auto parts to oem specs, they were all rated at 90 amps.

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No, my stock Pathy alternator was a 60, not the Maxima one.

 

I'm still waiting for the Maxima alty to get here (hopefully Monday)

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yea i thought the stock pathy ALTs were 60 amp.....

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Mine was a 60 as well.

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Yep.

 

Had a sticker right on the side "60 Amp".

 

Guess the early models got shortchanged.

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Ok did some more research, looks like the 80's pathy do come with 60 amp alty. Thanks for pointing that out for me! Well you get an extra 30 amp, as opposed to 20.

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Yep.

 

I'm salivating at the mere thought of it. -bounce-

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Yup, 60 amps on the 87-89's (V6 and 4-cyl) with 50 amps available at 2500 RPM's, per the FSM.

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Since using this alternator is a direct bolt in for mounting and given that you have to swap the trucks original pulley on to the new alternator, the belt remains the same.

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I had one small issue with my mod.

 

I apparently had an older alternator, with the fan shaped thing attached to the front. When I took the pulley off, it came apart in 2 pieces, front and back. When I mounted the pieces on the new alty, the holes in the old pulley were large enough to go down onto the shaft all the way to the front of the alty. I ended up having to fashion a spacer to set the pulley off the alty a bit, it was about 3/4 of an inch. Other than that, it was truly a bolt on replacement.

 

Still an easy mod and it works awesome.

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I just finished installing my '91 maxi alternator after my stock unit died. I didn't notice any difference in the way the truck runs. It's pushing about 15 volts right now. It really is a 'bolt in' job. I had a garage down the street swap the pulleys for free. I recommend taking apart your working junkyard unit to make sure everything is clean and well-lubricated inside before installing it. I also got my a/c compressor out so i can start lining up an alternator to replace it. The compressor and alternator mounts are very similar. I just have to figure out a way to put some tension on the old A/C belt.

 

Thanks for figuring out these alternators are swappable S.S.! You saved me some money today :beer:

Edited by skrillaguerilla

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I would highly recommend for anyone who is running a e-fan or offroad lights to upgrade their alty because this not only causes havoc with your electrical system, but the tranny can be affected as well and can lead to damage, like what happened to me pssd.

 

Tools required:

Ratchet

12 mm socket

10 mm socket

Phillips head screw driver

 

The process to install the new alternator is pretty straight foward, and a direct bolt on. First thing you want to do is look for your donor, the alternator that would fit into your 86-95 pathy would come from a 85-94 maxima. Make sure that you are getting one from SOHC maxi and not a DOHC, especially with the later year maxi's. Here's the diffrence:

 

th_dohcalty.jpg

 

th_SOHCalty.jpg

 

As you can clearly see the mounts have diffrent angles. The other between the two is that the DOHC generates 5 more amps than the SOHC.

 

This is the diffrence between a pathy alty and a maxi alty:

 

th_DSC01021.jpg

 

th_DSC01022.jpg

 

th_DSC01023.jpg

 

The maxima alty is slightly more beefier than the pathy. Ok, if you decide to get your donor alty from a J/Y, then having it tested out at autozone or checker is recommended.

 

First thing's first. Disconnect the positive lead on the battery. Unbolt the tensioner bolt with the 10 mm socket and with the 12 mm socket unbolt the bolt holding the alty in place to the tensioner to remove the belt. unbolt both the two bolts that hold the alternator to the engine block with the 12 mm socket. I would recommend to remove the back bolt first, and then remove the front bolt, while holding the alty with one hand. Once you have removed all bolts, wiggle the alty slightly to remove from block. Disconnect the pos lead to the alty with the 10 mm socket and remove the ground with the screwdriver. It the screwdriver does not help, then you may want to use a smaller socket, I think it was a 7mm, don't remember. Remove last plug in harness. Take the both alty's to a shop where they can swap the pulley for you, unless you already have air tools. Once the pullies are swapped, take the maxi alty and install all factory wiring again. Start by reinstalling all engine block mounting bolts, do not tighten yet. Install the tensioner to the alty, along with the belt. Tension the belt acocrdingly so it is nice and snug. Tighten all mounting bolts, reconnect the pos lead on the battery and start the pathy!

Here's some pics of the alty installed:

 

th_DSC01084.jpg

 

th_DSC01087.jpg

 

Over all the swap should take about 30 mins or less. I'm pretty impressed with the upgrade. The tranny problem i had started when I installed an e-fan and ended when I upgraded.

Ok. Your description was very detailed and informative. My question is, and forgive me if it sounds like a dumb one, but would this work on a '91 path(5spd) as well? Also i've read that a 110 amp alternator from a Quest can fit. Granted the person who had it done owned an '88 path. I'll be looking foward to your info. Thanks. Law69

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Yes, it'll work on your 91 pathfinder.

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What a kick in the head....the Advance Auto Parts here sells the Maxima alternator cheaper than the replacement Pathfinder alternator. :wtf:

Guess that'll make this an even easier choice, huh?....

Edited by 95shakinPF

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I just started this project and I purchased an alternator for a 1985 maxima. As it turns out the one I got is only 80 amps. I found out they can be as low as 70 amps. So make sure you know what you are buying. Now I'm on the hunt for a 90 amp unit. I need the extra amps because I am going to try a HHO hydrogen generator installation. Does anyone here have experience installing one of these?

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Well, my alternator died 2 days ago and I decided to follow SS's advice. I have to tell you it went in as smoothly as an OEM part (I have my own impact tools for pulley swapping). I went to Autozone and picked up an alternator for a 90 Maxima (SOHC). It was substantially less then the direct replacement for the Pathy!! Now I'm cruising around with 20 more amps than OEM and for less spread woo hoo!!

 

THANKS!!!

 

-Colby

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Aftyer driving to work today on a jump pack with a ratchet strap holdign my hood shut I decided to do this today. Useful info one tagged for a 94 Maxima had a different plug than my 88, one tagged for a 92 had correct plug. I did also go from an external cooling fan on the alt to internal(due to the jump in years I would guess) and had to make a small spacer to keep the pully off of the alt.(Cut an old un-warrantied socket down to size). It's nice to be charging again and with a little extra juice to boot.

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Autolite 14661 @ O'Reilly

Just installed it; 95 amps & dropped right in (after swapping belt pulleys)

and now headlights are much brighter.

Edited by MikeV

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