OK, I was able to download the schematic referenced in the original post. It is
here, for those wishing to follow along. OP, please verify that this is the correct schematic on Page 36 for your Allegro.
The schematic shows a single main ground point for the A/C functions. The ground is connected to a terminal block (Pos. 24, WB) and then connected to the other devices in the system.
Suspect also, if clutch won't engage would be the main relay as I believe power to the clutch relay is from the main relay.
Is there something problematic about taking the RV to a Workhorse service center?