I too have found the wiring diagram disappointing, but Ive been trying to figure out the ground and bonding wire locations.
For the interior lighting
, there's a bundle of wires running forward on the stbd side. IIRC, it reappears in the cupboard in the head, and splits up there. Some wires go forward for the bow lights
, some stay there for the head and stbd salon lights
, some manage to go up the mast (not sure where). I think the wires which power the vberth lights
flip a U-turn back to the port salon light. The galley light has its own connection behind the fuse panel.
FWIW, wire on boats should be pre-tinned along its length, this prevents corrosion (which would cause the wires to burn out sooner) - this is why marine use wire is more expensive. Ive seen both in my boat, the regular wire just comes apart.
Hope this helps. A report of your findings would be appreciated.
Best of luck!