I have a new multiplus connected to a 400ah battery bank through the Lynx distributer. Also have 120v shore power to ACin. I read 13.4v on the DC in side at the multiplus terminals and 110v on the AC side. Nothing happens when I hit the on button - either for inverter or charger. DC side is 4/0 cables with 400 amp fuse. AC is 10AWG through a 50 amp fuse/breaker. Not an engineer. Thanks.