Update: The circuit does work intermittently (maybe every other time). When the solenoid does activate to allow power from the chassis battery to feed the coach battery, I tested the voltage on the white wire that activates the solenoid. It fluctuates pretty regular between 14.2 volts (engine alt. voltage) and 4.7. It will stay at 4.7 for 60 seconds then jump to 14.2 for 10-20 seconds and then go back to 4.7 volts again. When it was doing this, I disconnected the orange wire from the ignition and when tested, it was a constant 14.2 volts. So in theory, there is something in the box intermittently reducing the current to the selonoid; i.e. circuit board, relay or that battery control module. When it does reduce the current, the solenoid will stay activated; however the reduced current does not seem to initially activate the solenoid.
At least we know that the circuit DOES work occasionally. First time I realized that was today.