Maybe it's just me, but doesn't sound like a connection thing to me at all. I'm going to say that your inverter is probably bad or the in-line fuse blown.
You ran the genny for 2 days, then started the RV, turned it off and then kept the genny running. Maybe you had just enough juice left in the batteries to turn the engine over the first time, but not enough to get it going the second time. If the inverter isn't getting juice to the batteries, the generator slowly drains them, much like the car engine would if your alternator stopped working. If all your batteries, including you chassis battery, are in series, they'll all drain and not just the house batteries.