[Y-Blockhead]

Originally Posted by Chuck Dempsey

About six years ago I bought a positive-ground 6-volt alternator from Mac's. I've put less that two hours on it now and it developed a minor short. I say 'minor' since touching the wire to the alternator terminal doesn't create a visible spark, but does set the ammeter to 'twitch' discharge. It did it last week and killed my battery overnight. At that point I re-wired the terminal box thinking that was where the short was. That 'fixed' the short but now it is back, and I've traced it to the alternator as described above. So I suspect re-wiring the box didn't really help at all. Any ideas before I remove it and take it to a shop?

Thanks!

Sounds to me like one of the diodes in the internal rectifier is bad, allowing current to flow backwards, thus draining the battery. Should be easy fix.