Reading wiring diagrams is not something I ever learned. And holding a degree of any sort does not make one smart. Since my first engineering job, I've not done electrical design. All mechanical. I'm glad you've experienced all you have.
The thing is, you just about have to re-learn reading diagrams everytime you pick up something different. Ma, in 73, completely changed the way the 73 A body diagrams are displayed. Old ones are "line drawings."
GM, Ford, have their differences, and all the "newer" stuff (Dodge Rams / Dakotas, etc) are different yet again. About all you can do is "dig in" and start looking
I used to work in HVAC/R service. Those diagrams were MUCH different than the electronics/ communications/ RADAR stuff I'd worked with earlier. And, Lennox/ Carrier/ Coleman are all quite different from each other.