I went through all that with my XLV750 - the battery died, fitted a new one....duh, no charge, dead alt. I got a complete engine from Malcolm for the price of a rewind. The stator had CDI charge coils that had been replaced....and a few months later one of the CDI coils in the stator died. When I fitted the stator it had white epoxy on the winding, when I took it out they were dark brown....hmmmm. Had one rewound, fitted and checked charge rate...all good at 14 or so volts. A month later it was fried. Another rewind and check of reg/rec - that was the problem. Although it was charging the battery ok, it was dumping everything to ground and overloading the alt. I don't know if it was the reg/rec all the time, or if it went haywire somewhere in the other steps of the drama, I'm puzzled that I always had a good charge when stators were replaced, so never looked deeper. But with a Japanese bike of that vintage - it's always the reg/rec.
okey dokey..the saga continues, fitted new reg/rec on saturday and still no luck, nothin gettin to the battery and i cant detect anything coming from the alternator at all, a mate who's handy with a multi meter tried every which way but no readings whatsoever, put some power through the stator and it came back out the other end but i dont have a megger tester that can whack 1000 volts through it. auto sparky recons he got charge out of it lastweek but i dont see how, will consult him tmw but looks like in up for an alt rewind after all. must also mention the reg/rec was rooted..opened it up and it'd had a short, question could a buggered reg/rec load up and ping the stator?
It was common with smaller 1980's suzuki's (GS450, gsx 250 etc) to have the alternator putting out the full charge current all the time, and any excess charge was lost by the regulator by shorting out the windings. This resulted in the regulator getting hot & so did the alternator which gets oil cooling (sort of). Unfortunately the regulator sat behind the a side cover & didn't get any cooling, causing it to burn out & sometimes take the alternator with it. The fix for it was to get any aftermarket regulator. If your alternator doesn't have any brushgear & has a rotating magnet to excite it & the whole lot is in oil, then you have this type of alternator. Hope this helps
Bring it over Ed, Have you got a wiring diagram?
what Rubber said... was also true of the bigger zooks and most japs of the era. shorted reg CAN take the alternator out
