Most of these motorhomes have an isolation relay between the chassis battery and the house batteries. There could be an issue with that relay.
What I'd suggest to do is either call a skilled mobile tech or take the Chinook to an RV service shop and have them go through the different wiring issues, test the batteries, test the alternator, and test the isolation relay. Nothing in your coach needs to be wired "hot" except the radio memory. You have at least one misguided user's (previous owner) ideas about how to power devices.
