I found the "Run Only Power" circuit. There is a circuit from the chassis that is only hot when the ignition key is in the "RUN" position. In the "Start" position certain accessories are disconnected from the battery circuit and reconnected when the engine starts and the key is returned to the run position. The Battery Mode Solenoid, is one of those accessories.
When the engine starts and the key returns to the Run position, the solenoid is reactivated and the coach and chassis batteries are coupled and both charge off the engine alternator.
Now if this happens again I can trace both circuits and find the failure in the circuit.
Thanks for the answers Guys.
