Generator Not starting unless coach engine is on

Remember the batteries are at the rear and the gen set is up front. That means quite a run of cable to connect the batteries to the generator. As someone else said, check the cable connections at the rear of the generator. Unfortunately, Monaco usually did not use continuous length battery cable runs and put splices along the way in the cable chase. These splices have been known to become resistive over time. If that is the case the best solution may be for a battery up front as suggested.

Bob