I have noticed that when I start up the bus and let it run, I am seeing in excess of 15 volts on the gauges, both house and chassis batteries.

Additionally, my inverters shut off and the display for each indicates over-charging of the batteries.

So, am I correct in thinking that the voltage regulator needs replacement or simply adjustment?

And, if adjusting the regulator is the answer, how would it have gotten "out" of adjustment, or does this indicate that something is going on with the alternator?