Trace that wire back through the harness, and I'll bet you find that someone has wired it through the ignition switch. That's definitely wrong, as it adds resistance to the charging circuit just as a set of dirty cutout relay points would. Try this: temporarily connect a heavy wire, 10 gauge of so, from the Battery terminal of the regulator to the end of the hot (+) battery cable at the starter. Leave the existing regulator wire disconnected, but don't let it short out to anything. (Tape it if necessary) Run the engine, and see if the voltage is correct, and if the idiot light stops glowing. I'll bet you solve the problem that way. If so, make the modification permanent by taping the heavy wire into the loom, connected that way. Insulate the original Bat. wire, and tape it into the harness for future use as a switched 12V. source if needed.
Jerry
Edit: To anyone who has an ammeter instead of a no charge light- - - - -don't bypass your meter with the above fix. It will keep the ammeter from functioning, and might mess up other electrical functions. The idiot light should continue to work with the above fix, illuminating full brightness anytime the generator is not charging. If it doesn't, better scavenge up an original-equipment wiring diagram and start chasing wires!
Jerry
Last edited by Hotrod Lincoln; 01/01/2009 1:56 AM.