After I mounted my LCD voltmeter I saw some unusual behavior. The battery voltage readout would indicate normal charging voltage for awhile, and then would drop (a few volts) into a net discharge condition.
The wires from the stator to the regulator needed to be replaced. At first, it appeared that the 30 amps being carried by the wire had just overheated a few inches of insulation next to the high-resistance bullet connectors. But, when I removed the common sheath that the wires run in back to the left engine cover, I found that overheating (from the current, not the engine) had softened the insulation to a degree where I could peel it with my fingernail. A multimeter says it's OK but at the higher AC output levels the wires short together. Remember, the wires are touching along the entire sheath length.
I didn't need to remove the engine cover. Inside the engine the wires don't touch each other. The approach that I took was to replace the damaged wiring (with a larger gauge to reduce electrical heating) up to where it exits the side cover. I pushed a piece of shrink wrap tubing over each of the wires and into where they pass through the seal in the cover and left the internal portion of wiring alone since they are separated inside the engine. The main problem is that they touch each other along their length where they run in a common sheath.
I also took the oportunity to relocate the regulator itself.
You can read the full explanation here:
http://ducatisportingclub.com/contro...d.php?tid=2042