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260Z gets a Frontier alternator


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I haven't been happy with the charging system in the 260Z for a while. At startup, the alternator output was fine, but after a while of driving, the voltage would drop down to only 12.8VDC many times. It was time to explore options. Since I converted the carburetors into throttle bodies for the Patton Machine GM TBI fuel injection, I wasn't using the neutral (yellow) wire from the alternator for the fuel pump relay #1. That meant I didn't have the limitation a stock 260Z owner would have. (Of course, I could have worked around that one if needed.)

Because I like experimenting on my projects, I decided to look into the Nissan Frontier 70A alternator. Since I didn't feel like paying ZCarDepot $150 for their setup, I searched RockAuto and found a new SKP for $86.79 (minus 5% discount and plus tax and shipping) alternator for a 1999-2004 Frontier 4 cylinder. On Amazon, I found the pigtail for the alternator $10.99 + tax. 

I took out the old voltage regulator (still a points style - Sorry, @Dave WM, I didn't try to adjust it first. It looked bad on the bottom to me.) and found the bottom side full of helicopter seeds and somewhat corroded. I tried some different bullet lugs to see if I could connect wires to the engine harness to run to the pigtail. That was a no-go. However, I found some alternatives. The white/red wire to the alternator positive had a smaller white/red wire with a female bullet to connect to a condenser on the old alternator. I would prefer to have a different sense wire, but it would work. Then I noticed that the condenser at the VR  was connected to the black/white wire. There was my switched source. I would just need to make a small jumper harness to connect the pigtail and condenser to the black/white wire.

For the most part it was a matter of removing the old alternator and installing the new one. I did have to replace the lug on the white/red wire because the positive post on the new alternator was much larger. That was no big deal, though it took some time to enlarge the hole on a 1/4" lug to make it fit on the M7 (or M8?) post.

I shot some video that I need to edit that may help others with the swap. I'll see how it turned out and post a link.

Here the Frontier alternator with the 260Z externally regulated alternator.


Here's how the wiring looked when I was done with the installation.


Here's the pigtail on the alternator going to the positive post for sensing voltage.



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From the wiring diagram to show where I got the sensing voltage and the switched source:


The black/white wire is below the voltage regulator in the engine bay. The white/red wire branches off the 10 AWG white/red wire that goes to the positive post on the alternator.

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1 hour ago, zKars said:

Fabulous!  Love it when upgrade stuff bolts in. 

Can you post up the part number of the pigtail you found? Thank you!


Here's an Amazon link: https://www.amazon.com/dp/B07ZMN2B59

You can find them on ebay, too. Just choose the 2 wire harness: https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=frontier+alternator+harness&_sacat=0

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I think we owe kudos to Z Car Depot for showing that the Frontier alternator fits, has the proper pulley, and has higher amperage.  Too bad the instructions he provided are so poor, he opened the door to your discovery.  The wiring is pretty straightforward, once the Sense and Lamp wires are understood.   More complicated for the 260Z of course, with the fuel pump wire.  And the 76 280Z has the brake check warning lamp to worry about.

Most people go for more amps because of low amps at idle RPM, causing dim lights and slow wipers.  Do you have an idea of if the Frontier unit provided higher idle amps with wipers, lights, heater, etc. on?  Driving through a storm on a cold night.

Edited by Zed Head
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If the brake check warning lamp works with the ZX alternator, I don't see why it wouldn't work for the Frontier alternator.

I should note that I did not have any backfeeding issues with the Frontier alternator like the 240Z has with the ZX swap. Since I didn't experiment with swapping a ZX alternator in first, I would have to study the wiring diagrams in more detail to see if the black/white wire in the 260Z that I used for the switched source is wired differently than how the similar wire is in the 240Z.

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indeed how is the voltage at idle when fully loaded with demand. I have stock setup including no extra items that increase current draw over the OE needs That being said I do go into a slight discharge mode when idle is at 800 rpm and all electrical is on (head lights, fan, AC clutch, blinkers, wipers) That being said its only at idle, as soon as I get to about 1.1k rpm I am in charge mode (I have an ammeter not a volt meter on my 75). My work around was to bump up the idle when the AC is on to about 1.1k rpm. This keeps me in charge most of time when sitting still in traffic as the AC comes on a lot here in Florida, and the fan draw is generally what puts it into discharge mode. 

Edited by Dave WM
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