Freightliner Dash Assembly redo

Sounds like a big project.
The last Coronado I drove was a 2012....... it was a completely different layout.
Not sure if the dash would actually fit in a Columbia...

 

I was, guess I still am. a commercial electrician for twenty years before I started driving. The wiring isn't as bad as you think. What you need to do is focus on the individual wires, rather than the giant rats nest of wires. Many of them will be numbered, corresponding to the wiring diagram.

What I would do, is individual tag ( mark ) with a piece of tape, each wire, and what it is for; positive or negative going cab lighting control. Some switches will three to five, mark what switch it is, and the number of the terminal on the switch.

The devices your switches control, don't care where their input comes from as long as it comes. Electric current doesn't care what color wire it flows through. Things are colored a certain way for our recognition.

All your switches are draw bridges. The signal is traffic waiting at the bridge. You flip the switch, the bridge goes down, the traffic flows across, until you raise the bridge.

It just takes time to label everything correctly. But believe me, the more effort you put into labeling, and marking everything, one at a time as you take it apart, the far easier, and more successful you will be on the re installation.