I bought a NipponDenso clone alternator from Autozone, 'Duralast gold', early this year. It was not much more money than rebuilt. Made in Malaysia. Delivered to doorstep in less than 24 hours of placing order.
I did not have the time or place or inclination to open up and inspect the failed 'lifetime warranty' alternator of a different design.
I work my externally regulated alternators hard, charging well depleted batteries with voltage I choose manually and watch the amperage flowing into depleted battery closely.
It was supposed to be 50 amps idle and 120 amps max.
It cannot meet that 120 amp rating, and when hot, it can make about 32 amps max, but a few hundred more rpm and it shoots up into the 80+ amp range. The failed alternator was indeed good for 50 at hot idle and 120 Max.
The alternator it replaced was a lifetime warranty unit bought from Kragen in 2004ish. I went through no less than 4 of those in 16 years, the most recent exchange in 2015. This most recent exchange, seemed to perform better at hot idle than previous ones.
O'reilly's, when I called them to get another one, claimed to have no record of me ever having bought an Alternator from them. I think after 5 or 6 free replacements, I got erased.
Since I realized it was not going to be warrantied, I opened it up to inspect a few weeks after installing the ND clone.
It failed, as the Brushes were not properly aligned with the slip rings, the lower brush just barely touching the top ring in in addition to the bottom one. When the brush bottomed out on that space between slip rings, it stopped charging.
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Looks like they missed, badly. Surprisingly it worked fine for 4.5 years like this~25k miles, and often, it was told by my adjustable voltage regulator, to make everything possible towards its 120 amp rating, feeding a large depleted low resistance AGM battery, over a thick copper circuit.
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I realigned the brush holder, rehoned the VERY out of round slip rings, removed the thermal transfer blocking paint on underside of twin rectifier plates, Made fatter copper parallel AC straps, and returned it to service, as it performs better at hot idle than the ND clone, and seems a smidge or 3 better than before with better rectifier heatsinking to casing and fatter AC straps.
The New made in Malaysia Duralast NipponDenso clone is in its original box, on a shelf. They sell both a 50/120 version and a 40/90. If it was not able to max out @ 108 amps, I would say they were selling the 40/90 as a 50/120, due to poor hot idle speed output.
I suspect the stator windings are a bit short of copper compared to An Authentic Nippon Denso. 108 amps was the max at about 2400 engine rpm and plenty of load.
It works, I was just hoping for the opposite of what happened. Its output is quite good from ~800 to 1300 engine rpm, but my other alternator is able to produce more amperage outside that rpm range.
I thought the dual internal fans would help its hot idle speed amperage output compared to the previous designs one pully mounted external fan, but that failed to materialize, and a smaller dual V belt pulley would have to be machined, so the older reman is back in place.
I removed the ND clone's back cover, voiding warranty, to see if there was anything easily improved like on the other alternator, regarding reducing resistance and improve thermal transfer from diodes, but saw nothing that could easily be accomplished, and put it back together.
So the New alternators, that are not much more expensive than Reman, are, in my limited experience, built to a lesser standard. Copper is expensive and there is supposed to be a lot of copper in the stator.
Acceptable performance, if I were not requiring maximum output often. I bet 99% of people would never notice its lack of performance, unless they were idling excessively with All dc loads on , and a well depleted healthy battery , and notice battery voltage dropping and dropping.
I bet this can occur with many vehicles with OEM alternators. Hot Idle speed output, with a heat soaked alternator, is likely unimpressive, and perhaps inadequate if ALL the possible DC loads are turned on while idling. But ti would likely take 10 hours of idling to fully depleted the battery, so really of little consequence.
for Cardone remanufactured products.
