It has been my experience that when a regulator or brushes go out, it does not alert you with the "idiot light". Wish it did!

I believe the light pops on if the one of the diodes goes out.
I have replaced this diode ring and made the alt work again.
I find these alternators easy to disassemble and combine parts to gain a useful example.

But, if your alt is a major PITA to get in and out-get a good rebuild.
If price is an issue, you might have some good luck at a yard finding a recent genuine Bosch rebuild.

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"