Battery disconnect Off/ON, it is a weird double negative, albeit I have seen them wired up backwards also.
Best answer is to check the battery voltage with a volt-meter. Is it like 13+ volts, then what the setting is correct to charge the batteries, if it is not 13 and some, switch it the other direction is it now 13+ volts, that is the new setting to make sure the converter will charge the battery.
Switch the “disconnect switch” to the opposite setting, wait 15 mins, did the voltage go down?
Now you know which is the way to make sure the battery will be charged by the converter.
