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Alternator- regulator issue?

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#21 DanielC


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Posted 29 November 2017 - 05:33 PM

In my experience, getting a 50 amp alternator from a similar year Datsun is a direct bolt on, the external voltage regulator does not even need to be changed.  The positive and negative wires should be changed to something thicker to handle the extra current.

You might have to get a new belt, to keep the laternator closer to the engine, and away from the steering idler arm.


There is a black wire that goes from the alternator case to one of the screws that holds the voltage regulator to the inner fender.  This wire is very important, it grounds the cab to the engine, and the battery.  If this wire is missing, the cab will try to ground through the throttle cable and destroy it and possibly leaving you with a throttle stuck open.  There is also a black wire from the alternator case to the negative battery cable.


This is the alternator on a L-18 engine in one of my project 521 trucks.   This alternator came out of a Nissan Pathfinder, Pathfinders are real common in junkyards in the USA.   I do not know what Nissan calls Pathfinders outside of the USA.

The L-16 engine in a 521 originally came with a stamped steel lower mount, held with M8-1.25 bolts,  If you have the stamped steel mount, your alternator fit may be different.
This shows the bottom alternator mount.  The mount is the same width as the space between the mounting ears of the alternator, and more importantly holds the alternator in the correct forward and back position for the V-belt grooves to line up properly.
This is the top mount for the alternator.  The slot for the top mount actually matches the radius the top mount bolt moves in.
A better view of the top mount.
This shows the view looking down on the belt, in pretty good alignment.

#22 wayno



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Posted 29 November 2017 - 07:14 PM

I have a couple of the lower ones in the photo below that Dmike posted, but I thought I got them off the Z22 block, anyway I was able to use the larger alternator with that lower alt mount and not hit the water outlet above.




I actually made a mount myself and the when I changed to the lower mount I noticed that 1 of my mount bolts had broke off in the block, so I will be removing the block in the next few months and will extract that broken off bolt so I can use all 3 mount bolts.



#23 mainer311


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Posted 29 November 2017 - 07:18 PM

With the 60A alternator swap, I ran 6awg wires for both power and ground. Something I found with old Datsuns, the more grounds, the better. It’s also highly suggested to run a fuse/fusible link inline on the power side.

The alternator I bought that fits like a glove is a Remy 14118, from Rock Auto. It’s a remanufactured Hitachi. There is a small interference with the top adjuster and a fillet on the aluminum case right where the upper flange meets the case. I filed the fillet with a rat tail file and that was it.

The belt is either a 15350 or a 15355. I forget which one I used. I can look in the morning.

#24 datzenmike



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Posted 30 November 2017 - 07:47 AM

The two mounts I posted could be backwards description wayno. It was probably 20 years ago.

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