Marlin grounding

[Angler Management]

I’m reconfiguring my battery supply. Two starting batteries one for Port one for starboard and a house bank too.

I’m confident of all the hookups in the battery compartment, and would lik to assure from another source what exactly the batteries ground TO?

Basically what’s the grounding/bonding schematic for my 2007 Grady with original 250 Yamaha’s?

 

[Angler Management]

I think I found my answer, it appears to be Starboard motor on my boat. Unsure as to how it all works exactly, but as long as I’ve got my negatives all ending up tied to the same point, including motors, I’m good.

?