The ground for the fuses in the front run box is a single wire at the bottom of the fuse holders. If that fails, all that stuff will fail.
I have grounding bars on both sides of my engine compartment that service different components.
If you have the rig's Owner manuals mine has a schedule of the wire numbers in the coach in a "from/to" format.
Although, ground wires are not displayed on the wire list. They are typically displayed on the schematics.