sorry for dragging up an old topic.. but I've got a problem relating to this:
I've got a 1949 fiat topolino with a mechanical regulator with three relays inside and a resistor on the back. basically, I keep getting carbon built up everywhere, on the generator commutator, and on the middle relay.
at idle all the relays stay closed, but if I rev it up two of them start to cycle together, one with low-current looking points on it, and one with fat ones.
the one with fat points sparks every time it cycles, I think this is part of the problem as thats the one which cuts the voltage back if it goes above about 13.8v. after about half an hour of driving it stops making contact through the carbon that's built up and my battery light comes on, cleaning it with fine sand paper gives me another half hour.
what would cause this problem? have I got a short or partial short somewhere which is causing too much current to go through that relay?