Its the exact same setup I had before but WAY less messy and now color coded so I actually know what is hooked up to what. I went from 11 plugs to 5 (eventually down to 4) and the nest of inconsistent wire types and lengths are no more. I even have 2 spare circuits ready to go.
So I started down this road back in may 2018 and yeah. I decided I needed to get all my pet projects done because in a few weeks I will start a grad program and have no life™.
So it go like this.
Big-ol-battery (odyssey 105 aHr) to 120 amp breaker to bluesea dual buss circuit block with negative buss. Buss A is battery hot, soo all the power all the time. Stuff like the fridge and camp lights go here. There is a jumper from A buss to a 60 amp breaker then onto a 120 amp relay that is triggered when the ignition is on making all of Buss B ignition hot. This is for radios and USB ports and such that come on and off with the car.
Also, on Buss A are 3 independent relay circuits that are switched (2 in use, auxiliary cooling fan and light bar). They are triggered to be ignition hot like Buss B on the same trigger source but individually fused (the second fuse block takes the signal off the cigarette lighter and splits it into 3 separately fused trigger sources). I could have put them on buss B but they are both high amp and with everything else on B it would have been too much current. This way I also have redundancy with replaceable relays instead of relying on the big-un only. Needlessly complicated? YOU BET!
This way I have battery hot, ignition hot and switched circuits all in one unit that I can take out easily if I needed to move it to another vehicle.
*yeah....its not done. Mainly because I need to find a better way to secure the plugs, but I’m pretty happy.