Egnine Battery Dead
 

After a month or so storage the engine battery is very, very dead, even if it is plugged into shore power. So there must be a drain on it. The battery is new prior to storage. Any ideas? Thanks.Will Procter

Your coach is much newer than mine and probably wired totally different, but I have to set my battery merge switch to on in order to charge the starting batteries from the inverter/charger when plugged into shore power.

When you changed the chassis-battery were all the connections, grounds, checked and cleaned throughout the starting circuit (includes; solenoids, alternator, and starter)? Any poor connection or ground can reduce voltage needed for engine starting.