No power to Coach

[Camperman]

Hello, I have a 2006 Sun Voyageur. I just charged up the 3 batteries after a very long cold winter and after installation the engine (gas) fired up on the first turn of the key. Turned on the generator and it fired right away. Everything seemed to be working so I decided to leave the generator running for an hour or so and turn off the engine. The generator also shut off. When I checked there was nothing registering on the panel for water, battery power etc. No lights either. I disconnected the batteries, cleaned all posts and connections but the only thing I did not clean was the ground for the coach batteries. Turned on the engine again and everything seemed to work including interior lights, panel, generator etc. Turned off engine and tested the inverter which is getting 13.8 volts but nothing coming out.I'll clean the ground tomorrow morning and see if that helps but it seems to me that if that was the issue the inverter wouldn't be getting power. I checked the kill switch at the door and while the engine switch "clicks," the coach switch doesn't. I'll check that tomorrow also. Hope that's the problem rather than the inverter. Any suggestion on what the problem could be? Anyone experience a similar problem?
Thanks.
Mark