Hi Steve,the most common problem is wire strands breaking off internally at the regulater plug.Alternaters need juice to make more (no magnets) The heavier regulater wire,pretty sure it's red, ties back into the charging output wire (batt) in the harness near the back of the passenger side valve cover,so it should have battery voltage at all times. The other regulater wire (white?) should be switched Ignition source. If you put just any batt source to it,you can't shut the engine off. (backfeeds) Hope this helps you,Hank