when I re-wired my Tahiti, I used Berg 7-wire. This is used to wire semi truck trailers. 1 12 gauge wire and 6 14 gauge wires inside, all nicely color coded. I ran an external 12 gauge wire as a ground. These supply power to my fuel pump, bilge, etc, etc. The MSD is wired direct to the battery, and my Holley fuel pump, has a relay which is wired to the battery direct as well.