Good morning,

I have similar projects.  I use Visio now, but it is not the right tool.  Pro's use Autocad or Solidworks and the various add-ons.  Expensive and hard to use unless you use them for a living.  I found this tool, it's open source and free to use.  It is built for wiring diagrams.  I am trying it out now. 

https://qelectrotech.org/

Look at the Gallery first.  If that level of drawing is what you are after, then go for it.  I have been able to get by with pencil and paper for a long time, but I may be doing some of this work on the side after retirement so better get my documentation up to snuff.

Thanks very much, I wlll give it a try

@brier_john I've also used Visio in the past as you can create custom components with connection points and if you need to move them around the connectors will re-route with them.