The ground which caught glad rags eye caught mine. It appears to be a graft, or, occupies the insulated portion of the conductors. It attaches at the aluminum frame rail. Following the rail to its terminus at the bulkhead, we see evidence of fire or arcing. If the ground becomes hot (+/-) then the possibilty for dead short or polarity x suggests a source of lost power, or arcing/heat/ignition? Wherever that rail travels elsewhere? Shouldn't that suggest the need for isolation?
Some day some knucklehead is going to use those red taped connectors for a step.