I can't address how your rig is wired/setup but the basics may help. SWM receivers do not supply DC to the LNBs, instead the power inserter supplies the power.
So the basic SWM connections: The single dish coax cable goes to the dish controller (if so equipped) input. The dish controller coax output goes to the power inserter dish input. The other power inserter coax goes to the SWM splitter. The other splitter coax connections connect to the receivers (or if DTV Genie the reciever and the Genie Clients). No splitter required for one receiver.
There can be a lot of variations in rigs. The power inserter supplies DC upstream to the LNBs and sends the sat signals downstream.
So you must have a power inserter and it connects/plugs into AC.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland
Bob