Years ago when I did my Buick V6 conversion I had a 1-wire (self exciting) GM alt built for it. It is now bad - when I rev the engine to kick it in to the 'charge' mode the output increases from the 13V at idle to 14V (which also seems low), but when I let it go back down to idle RPMs it does not stay at the 14V charge output as it should, but drops back down to 13V.

My question is:
What is the difference internally between the 1-wire and a standard alt?

I compared it to the standard alt from my spare V6 and the only difference I see is a 45 ohm wire wound resistor between 2 of the terminals on the regulator. Other than that, the regulator, diode trio, and rectifier appear the same (although they're both to old to compare part numbers, so I can't be sure).

Is this resistor all it takes to convert a standard alternator to a 1-wire type? And therefore I can just stick this resistor on the spare alt and use it?

Thanks

the resistor is for radio noise suppression, it sounds like they both are internal regulated units. just a thought how is your battery? it can cause the same symptoms.

Yeah, they're both internally regulated, but the one is self exciting.
I found out that the difference is the regulator although they look the same. Just need to get a new regulator.