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I have a 100 amp one wire alternator that only charges at around 2500 rpms. I have another one wire alt that is 65 amps, but the bearings failed prematurely, and as the bearings went, it seemed that it started only charging to 12.3 volts it never went more than that. And even before that happened it never charged over 12.7 volts, and this was a brand new alternator. Is there any way I can make one good alternator with these two? I would rather have a 100 amp. I have a '68 Camaro, but it has an aftermarket fuel injection system along with the electric fuel pump, and a/c. If you have any suggestions, they would be greatly appreciated. I took them both apart, but I am not sure what makes them 65 amps or 100 amps. How can I make the 100 amp alternator charge at a lower rpm? Thanks for any help.

The number of turns is related to voltage and speed. The higher the number of turns the slower it needs to turn to produce the same voltage. The bigger the wire in diameter the more amps it will carry. The problem with rewinding these to go at a slower speed and yet produce more amps is that the more turns and heavier wire are needed. I doubt it would fit the area allocated for it. The next issue is once the iron is saturated with flux it becomes difficult to drive an increasing magnetic field through a iron rotor and stator that is designed for the lower amps. The higher the amps the higher the field strength needed.

The most likely cause of the failure of the alternator in the first place is due to rectifier or diodes going bad or the brushes on the slip ring becoming weak or worn out or greasy. Another possibily is burnt windings. If this is the case you should be able to smell this if you get close. One could repair some or all of these possibilities however, the easiest thing to do is to use this as an old core and trade it in for a rebuilt. Request the 100 amps or the highest amps available for that year of car-engine.

Offered by Mike.