In part 2 of this build, I get hands-on with the wiring and layout for my electric circuit monitoring unit—the one that lets me see voltage, current, and frequency on three separate 20‑amp circuits. I start by showing the testing setup I used to validate the key parts before I committed everything to the box. For me, that’s the whole point of DIY engineering: test first, then wire it like you mean it. From there I walk through the complete wiring, including how I handle the neutral wiring, how I wire the main switch, and—just as important—how I physically mount that switch cleanly in the enclosure. I also spend time on wire routing and closing the box safely, because sloppy routing turns into pinched insulation and mystery problems later. Finally, I extend the wiring for the current pickup coils (CTs) so the sensors can reach where they need to go without stressing the connections. The takeaway is simple: plan your wiring, label and route it intentionally, and build it in a way you can service later without ripping the whole thing apart.