Power supply to switch from battery

[Lobsterclaw]

I want to run a new power supply to the console, Have an 8 gauge marine wire to run.
Looks like a maybe 14 gauge to the console power switch from battery now, then same gauge to fuse panel.
Where does the ground wire come from and what color is it.
Looks like two purple color grounds connected to top of fuse panel.
One coming and one going? Hard to follow in confined space.
I'm having problems with tach and other gauges working sporadic so thinking ground maybe loose somewhere

 

[Wayne P.]

The negative comes from the other wire to the battery that you install with the positive wire you are adding.

 

[Lobsterclaw]

OK thanks Wayne

 

[Cyco]

Yes, I'd feed 2 wires from battery to console. + to fuse box lug to feed all the circuits, then there should be another bus bar (with no fuses) would be all your Neg. contacts. Should be a main lug to connect neg. wire from battery.