[lvhdude]

I had a similar problem on an unrelated vehicle. Problem was the signal wire to the Voltage regulator was not seeing actual battery voltage. The solution was to run a wire directly to the regulator from the battery. It's in an RV, and I didn't want to chase the wiring all through the coach to find the source of the problem, but that solved it, after haveing the alternator (w/built in regulator) rebult once, and replaced once. Might be worth a try just as troubleshooting.