I would guess you have a BCC (Battery Control Center) on your Hurricane and it controls the chassis / coach battery charging and use. On the Hurricane it can be found behind the engine hood, driver side. The "Emergency (AUX) Start" switch on your dash is part of it.
Also, can you monitor both (chassis and coach) battery voltages during these 'episodes'? Like you mentioned, the inverter is working now as long as AC is supplied so the lights work. The BCC manual has a short troubleshooting section.