Load test a bank of 6 AGM house batteries.

There are testers out there that use a small amount of AC current to test batteries but I really see no difference in using a carbon pile to test either one. A load is a load.

For the last 10 plus years load testers have been obsolete. That said a carbon pile can exert a load against an alternator to test it's capability. Now days they use a battery, starter, alternator diagnostic tester. They are powered by a 9 volt battery and merely send impulses into the battery and analyze the condition of plates. In seconds you get messages such as Good battery. Bad battery , Good battery needs charge needs charge . The sheer beauty of these testers is they take absolutely nothing out of the battery and no days of charging required such as after a load test from years ago. People selling and warrantying batteries are required to have these type of testers for obvious reasons . Can you tell I used to sell both carbon pile testers in the old days and the modern ones in latter years and own one of each. The modern ones are also small enough anyone could carry one with them . My units incidentally are Snap On

Are you sure the genset is started by the house batteries ? On my Newmar, I had thought the same, but while tracing wires, found that it is started via the chassis batteries..... and that there is a 40' cable going from the back where the chassis batteries are to the genset in the front. That 40' cable was compromised, resulting in my starting difficulties.

When de-winterizing I found that I have a bad water leak in the catch-basin where the hot and cold and bypass faucets are located in my 1993 Pace Arrow. The leak drained the fresh water holding tank into this plastic basin and found its way to the ground via openings around the drain valves to the ground. Question: how do I trace where the water is leaking from? Everything looks dry above this location. The pump works fine and no leaks around the clear plastic part enclosing the rubber diaphragm, and no leaks from above.