That should be a Paris Rhone Alternator in my original post.
It is an intenal regulator, attached to the back of the alternator. I've had the regulator tested at an auto electrical shop, and they can't find any problem with it. But when I put it back on the boat, I get the overcharging problem.
There are four connections on the back of the alternator/regulator. Does anyone know how these interact? How does the voltage sensing work in these
alternators/regulators?