That has a few problems, like the lighting and the battery meter won’t turn off when the loopkey is pulled.
Plus, learning to solder is highly recommended. Each of those connector pairs you need to cable-tie together (or tie with twine) so they can’t vibrate apart.
Try a circuit closer to this, and put the voltmeter in parallel with the lights.
Also, 10AWG wire will work fine but really 12AWG is all you need. Only use silicone-insulated, high-strand-count wire.