He explains everything including troubleshooting in plain language. There are 34 Chapters with titles such as "Oil, Brake & Warning Lights", "Turn Signals and Hazard Flashers","Switches, Relays and Solenoids".
I would not have recommended the book if it were no better than a wiring schematic, which, btw, are also in the book.
You've heard of books being described as "the---- Bible" ?
Well, this is the TR6 electrical system's Bible.