Newbie question here. The house has gone dark (on 12v only). The interior lights and fans etc. all work with the engine running/alternator power or with shore power AC. I have since replaced the circuit breakers coming off the house battery and checked for voltage at the fuse panel. Does the (+) primary 12v supply (black wire below) run straight from the CB off the battery to the fuse panel? I checked for continuity on that wire by detaching the black wire below and attaching an ohmmeter to it and then attaching the other ohmmeter lead to the primary off the battery - nothing! Does the supply to the fuse panel go first to the isolator? Thanks for any/all help