I'm curious to know why you had to run the rooftop A/C the entire time? We have only had to do that one time when it was well over 100 degrees outside and we had multiple people in the living area. Otherwise we are just fine with just the cab A/C. And ours is the "Black Magic" color (I think that's right) so it is quite a heat sponge.
So you know, I have found that if you run both A/C units, you will drain the rear diesel tank in about 3 days. It can really suck the fuel down with those running. But I just ran it 3.5 days with no A/C, with another RV plugged into me at the same time, and used 5 gallons.
There are a few things I think you need to look at. First, look at the inverter read-out inside the house door. It should say something around 13.6 volts. If it says anything around 11.5, you have a problem. For me, this usually means I need to reset the inverter. It can also be caused by that tiny breaker I have pictured earlier being tripped, which will prevent the genny from charging the batteries, which is a problem in your case because the genny takes priority over the chassis generator, which means the fridge will run the batteries down. Third, check the water in the house batteries and ensure they are topped off with distilled water at the correct level. All of these issues will cause a genny no-start situation.
