I'm thinking in the rv there are lots of connections to ground. Most everything is landing to the chassis in one way or the other.
Mine has a ground bus bar under the bed, in the area behind the converter where the birds nest of wires are.
The house battery has a connection to the chassis
the chassis battery also
and there's several wires grounded to the fender near the battery isolation relay (BIRD system) under the hood on the fender.
and on and on....
what problem are you chasing?