JimK-NY wrote:
I would start with some simple troubleshooting. Unplug the unit from 120v. Begin at the batteries and check the output voltages. Trace the wires from the batteries to the converter/charger system, probably an Elixir. It is possible a battery cutoff was installed. Check the input voltage at the converter/charger.
Since you have 12v power when using a 120v input, it seems the converter/charger is working and you will find a problem with the battery input to the unit.
It seems to have power at batteries and at converter. No switches in sight. Do they normally switch over automatically??