I don't know if the expanded guide covers this, but a lot of times a harness connector has turned to crap and because of that, the original Curly's guide could lead you to believe a component was bad when it was really just a connector. My problem was a homemade twisted splice that had turned to crap way down in the harness by somebody putting in a new fuse box. I rode to Texas barely charging, and finally figured it out down there just to get it off my mind.
If I had to do it over, the way I'd do it is I'd test all the relevant components separately disconnected from the bike, and if that didn't show up anything I'd buy a new harness! For solid state bikes, I think the manual includes an off the bike rectifier/regulator test, which is useful.