This thing may be a hell of a lot more complicated than some of you realize. I have seen a BUNCH of 24-12 100 amp converters on big buses, the 12 tracks the 24 at exactly 50% of the 24's voltage.
Therefore there would be ONE alternator one the rig and it would be 24 volt.
If the inverter fed off of the 24-12 converter (they have a low voltage cutoff) the inverter would operate off the 24 volt battery bank for awhile then cut out. If the rig were running the alternator would supply enough converted power to keep the inverter happy.
This means the 12 volt system is isolated. What on the bus is 12 volt? Something charges 12 volts like the rig's converter when it is plugged in and the generator's alternator unless it has a dedicated battery.
This needs to be examined piecemeal. One stupid wire left disconnected or connected to the incorrect terminal causes this.
The BRADY BMP21 wire marking tool in the right hands eliminates or drastically reduces the incidence or error.
Series parallel switches took at hike thirty years ago. The rig has to have some form of conversion to allow the 24 volt charging system to charge the 12 volt system. Find out from Prevost what they used and then troubleshoot that device first. Not necessarily for failure, but for a misconnected error.
