Battery compartment connections

Thanks All. I am concluding that the red positive battery cable is not connected to the frame (of course) and instead an insulated junction post as ndorder and others are pointing out.

Thanks as well for the tips to validate this conclusion.

Here is a closer up image in case it helps others down the road.

I too was a little confused when the OP used the term 'chassis' which means 'ground' to me. Here is a related link with interesting info a pics of a members setup. Its just for general related info.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28895570/print/true.cfm

Plug into shore power or start your generator then use a volt meter to check the cables. Make sure cables are not shorting before starting the test.

The only way to know for sure is to trace the wire back to whatever it connects to. Most common would probably be much as ndorder describes: it goes to the battery isolation (continuous duty) relay, the house battery disconnect (latching) relay, and the generator's 12V power connection. That said, there are many variations in the exact details.

Insufficient input data for efficient analysis/diagnosis, or to suggest reliable resolutions/answers/advice.
The most common answer is, a positive (+) battery terminal.

Are you worried that the cable with the red tape is connected to the frame? My Four Winds has a similar arrangement and that lug is electrically isolated from the frame. From that lug, the +ve is distributed to the isolation relay and the disconnect relay and to the switches that activate them. A continuity check between the lug and the frame would prove isolation.