Quote:

Powermaster's observation is correct; if swapping the field wires changes the output, the alternator is faulty...even if it works that way.



Exactly. That would be conclusive proof of field-coils(rotating)-to-ground current leakage.

This kind of stuff shows up more and more as the "cores" get older. Good rebuilders use an instrument called a Hi-pot to check for leakage, but don't count on that.

This is why the all-new alternators, even though Chinese, are probably a better bet (Autozone Duralast Gold, etc.)

Rick