Yes, it can be a bit challenging to determine "which wire is connected where", but logic wires can be used. Although they will be invisible (as intended), everything will still function correctly.
A handy trick that you could use to deal with the invisible spaghetti wires logic is to initially construct everything using vanilla electric poles, where the wires are visible. Once the setup is complete, you can replace the poles with the corresponding underground variants, and all the wiring will be preserved.
And I have the mod recommendation for you ... Circuit Visualizer. It's works similar to the more popular PipeVisualizer mod by Raiguard but for wires/circuits instead of pipes. Both mods indispensable, suggest you check it out.
@Giovy2001 Great mod by the way, and thanks for your efforts! Love it!
