I think this is sinking in, but I like this explanation so I’ll share it. Buss bars are like manifolds in your fluid analogy. It’s like an open plenum where electricity can flow freely between conductors connected to it. It gives you a convenient place to make multiple connections.
When you installed your fuse panel, you can think of each circuit as if it was stand alone on its own battery. The negative terminal is reached through the ground buss, and the positive terminal is reached through the fuse. Each fuse has one leg bussed together inside the panel, and the other leg is bussed to its individual terminal.
Always test resistance on fuses to establish they are still good when trouble shooting. Countless hours of troubleshooting have been collectively wasted because a fuse looked good. Many working components have been changed because someone couldn’t bench test the component and didn’t bench test the fuse. You can often see when they are burnt, but it takes only seconds to verify with a meter.
I’ve managed to wire lots of things without much more understanding than where you are. There was no magic, just route a wire, hook it up, see if it worked, fix it till it does and go to the next circuit. Once that’s done try to loom it and get looking clean, protected form edges etc. Sometimes I. That step I’m rerouting a wire and reterminating the wire because I left it too long.
Just keep going, right?
