Battery Disconnect Switch

On shore power, the switch should be "closed", which means the converter can charge the battery. If the switch is "open", the battery cannot run the 12v things when the converter loses its 120v input.

The battery being "dead" needs clarification. Low voltage at the battery posts using your digital multimeter? Or just no 12v in the rig now there is no power to the converter and the disconnect is open?

There is also a battery fuse or DC breaker near the battery on the pos side that could have blown (to open) that would have the same effect inside the rig as if the disconnect were open.

iceman31,

The switch needs to be on for charging to happen.

If I remember correctly, you can pull the handle out of the switch when the battery is disconnected but not when the battery is connected.

Just off the top of my head, either they've wired the converter output directly to the battery, in which case it shouldn't matter which way the switch is set, or they've wired it through the switch, in which case it would need to be ON in order for the battery to be charged.

Sounds to me like you have a problem other than the switch.