All but the initial alternator, have been remanufactured alternators purchased initially, once, long ago from Kragen Autoparts. I used that warranty, many times when they were Kragen and then when Oreillys bought out Kragen, they honored the warranty.
I can swap them out in 15 minutes in the parking lot. They cost me nothing, but the time to replace them, and the inconvenience of having to so so, usually right in the parking lot.
The initial alternator might have been original or not, replaced by previous owner.
I've worked them hard charging
. I will continue to do so. I'd like more amperage at hot idle speeds, but 50 amps is almost enough. I had little motivation to seek a better alternator when they were just handed out free. Now they cut me off. Kind of surprised they did not do so earlier.
Some Alternators lasted months, some lasted years. 4 years ago, I bypassed the engine computer voltage regulator with a 10 ohm resistor to simulate an alternator and not illuminate the check engine light. I now run an external adjustable Voltage regulator. I modified the VR's voltage trimpot so I could have a potentiometer on my dash to choose any dang voltage I want between ~13 and 16v though 30 seconds above 14.7v can illuminate the check engine light and cause engine to run crustier and get worse mpg. Need to reset computer when this happens.
I basically make it seek and hold 14.7v any time the battery is accepting more than 0.5% of capacity and dial it down only then, or if the alternator gets too hot.
I have attached a K type thermocouple with arctic silver thermal epoxy
to the stator/exterior casing of the most recent failure and insulated that area from direct windflow from radiator fan and vehicle movement.
I've lots of data Data with amperage output vs temperature at different rpm and vehicle speed and ambient temperature. Basically the danger
zone is hot idling maxed out, and slow speed low rpm driving maxed out. Maxed out at 65mph it would not exceed 140f, the Stator casing anyway, no Idea on the rectifier. Thereafter I avoid Idling to recharge, and if forced to drive slow with depleted battery, I lower voltage to 13.7 range to keep stator temp below 165f or so and raise it as battery charges, back upto 14.7v.
stores listed the Nippondenso 50/120 as a drop in replacement. I asked an ornery old contact who used to be heavily involved with alternators back inteh 80's about the ND vs the bosch/chrysler style alternator I had been using, Dual internal fans and 2 more diodes, he said it was likely to perform better at low rpm, run cooler.
I figured i'd give it a shot. New was 25$ more than remanufactured. It was delivered to my door in 21 hours, free shipping
166$ total. It has a 'limited lifetime' warranty, whatever that means in this day and age.
The output stud of the ND, comes out of the back of the alternator with about 5mm of room all around it. the Keyed protective collar slides into the receptacle and prevents stud from touching the grounded body should it take a lateral hit.
With this design, The Nut holding the collar in place, is the surface the ring terminal HAS to reside upon. Without a nut the ring terminal would rest on the bakelite protective collar, making minimal contact with the stud's threads. In this case the Nut HAS to pass current to the Ring terminal. Obviously poor design, but this design is obviously intended for a vehicle that rarely would ever seek more than half its rating, and only for short durations.
This Nut is steel. Steel has ~1/50th the conductivity of copper.
Conductivity Of Metals Sorted By Resistivity | Eddy Current Technology
The Stud and the Steel nut therefore have to transmit the electrons to the ring terminal. There is no wide magical flat spot for the ring terminal to rest upon the stud and the nut being merely there to hold in place.
The copper is obviously soft, the threads not strong. Perhaps I'll get a half thickness steel nut to hold bakelite protective collar to the back of the alternator. Then put a copper nut atop that, one which can grab all the studs threads tightly for lots of surface area, then the ring terminal which barely fits over stud, then the steel nut can go atop that and hold them all tight. Perhaps a high temp conductive grease to help conductivity further.
In the case of this alternator the steel nut provided HAS to carry a significant portion of the current. There is NO other option, with this alternator.
Making a copper nut, to grab as many threads of the output stud tightly is my task tomorrow. Hopefully I can find a half thickness steel nut to go below that and take the stress of the ring terminals being compressed on the copper nut/washers/ring terminal(s) above.
Until I am sure the alternator works, I am not considering removing the backside and inspecting how it is attached to the rectifier. All the nuts holding it together have the paint
across them to show if it has been opened.
I actually have No experience opening up alternators, other than the plastic back of the chrysler/bosch units I have been employing upto this point.
I'm going to work
this alternator hard too. I will collect lots of new Data. The output amperage should be directly comparable to the previous alternator, the stator casing temperature less so, but I'll collect it anyway.
I've not read the fine print of the 'limited lifetime' warranty, and I am not going to be mid atlantic when it fails, and can drive a good 180 miles, at night, if/when it does fail on the battery alone, as I did a week ago. But I'd like more reliability and I think the steel nut is a glowing failure point in the design, especially as hard as I will be working it compared to the average driver.
The previous one, of the different design, was making 26 amps total, 6 of those going into the 82f battery, at 14.62v, and the casing was 119f when it failed.
I've not opened it up yet to inspect it. I will though. I'd like to rebuild
it, make it as tank like as possible. Bigger better diodes, more heatsinking, ect.....