Newbie here with some rudimentary electrical questions

[gks314]

Brand new to the forum, and brand new to the RV world. I bought, 2 days ago, a 2017 Midwest Auto Sprinter (on a 2016 chassis), and I'm furiously trying to read through the manuals (I have most of them, and am downloading the others).

It is equipped with the standard Onan generator, Dometic roof AC unit (it also has the 12v ProAir AC), a Truma CP unit (which I assume is both a water heater and a van interior heater), as well as a Xantrax inverter and a solar controller for the rooftop panels.

The cab has a Master Power switch that turns on the power to the van's systems.

I'm sure that I will have a lot of questions as we go forward, but I'll try to minimize them by researching first.

Let me start with this one:
The generator (LP fueled) starts and runs fine (though I have to have the master power switch ON for it to run). My understanding is that the Xantrax inverter/charger should "see" that the generator is running and presumably supplying 120v AC power and should so indicate by showing me a green light. It does not. And the Dometic rooftop AC gives me an E7 error code, which (I believe) means that it is not seeing the 120v AC from the generator.

It seems like both the inverter and AC unit do not sense that the generator is running. Is this possible?