Headlights work, nothing else

[Accelo]

"I think it paid to take some time and sort through"
Almost always the case.

It is extremely difficult to do troubleshooting on the internet.
Especially if the person, with the issue, has little or no knowledge of electrical circuits and the tools needed to track issues down.
We all hope for the simple common solution, these are few and far between.
You had both the tools and diagrams needed. Throwing parts at it almost never works.
Congratulations on getting after it.
Cheers.