After many hours of tracing wires, I finally found how Winnebago ran the 2 wires from the 5 lights & fan (daisy chained yes). They were run down between the shower stall and the back wall of the RV.
I had to remove a small access panel for access to the plumbing under the shower pan. I was able to use coat hanger wire and grab the 2 wires and pull close enough to opening to run test on the ground side and there is continuity from this point to the lights etc.
Tracing from this point to the grounding source is my next step but I'm not going to put a lot of effort as the Bundles of wires in the harness is vast & runs in 2 different directions.
I'm opting at this point to just cut the Wire splice in new wire and run to a ground and call it a day. I'm running out of time before my trip starts and have to many other items to get done.
Thanks to everyone on giving some direction.
