LOL, glad you noticed, I live in the country and found that on the driveway by the rv, I thought it would be a better prop than MY wrinkled finger. I COULD have used my lawn dart, or my .380.
I just hope it applies to the OP. Neither of the last 2 RV'S I owned charged the batteries from the alternator but they were designed to. I installed battery isolators on both. I wanted the house batteries charged so we could watch tv off the inverter and not run the generator when we parked to eat lunch or whatever.
I don't have a 07, mines a 2000. Inside the rv electrical box there are solenoids, One is activated by the aux start button on the dash. This connects the batteries together and is also energized when the key is on so the alternator voltage gets to the chassis battery, that solenoid also has a fuse for the coil. Press the aux start button with the engine off and see if the solenoid clicks, if it does, the fuse is good. With the engine running, check across the solenoids big terminals, If you read voltage and the solenoid is energized, the contacts may be bad.
Have you check the fuse (under the hood in my E-450).
Is the isolation solenoid working correctly? (Mine had burned contacts).
Regards, Don My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.