One of the things I often do when working on electrical problems is to sit down and create my own wiring diagram. As Shelby pointed out, the wiring diagrams in the manuals can be hard to follow. I am attaching the handwritten schematic for my SK model of the the signalling electrics. It should be similar to your model, or at least get you most of the way there. There are two drawings on the sheet, OEM on the top, and what it looks like after I modified it, on the bottom. Stick to the top diagram. My shop manual is full of scraps of paper with my own schematics.
A couple of other pointers:
Corrosion on the connectors, switches, sockets can be hard to spot. They might look like clean contacts, but it doesn't take much corrosion to gum things up. When you are going through the circuit, make a point of cleaning every contact regardless of what it looks like. Contact cleaners are fine but in a lot of cases you need to go at it with something better. I still have a relay contact cleaner that I use. An abrasive pencil eraser will some times do the trick.
Go through the circuit starting at the battery and work your way along, writing down the voltages as you go after every device/connector. You may notice a gradual voltage drop as you go along. This may be normal. Larger drops in voltage are more of an issue.
I assume you have a voltmeter. If you don't have one then get one. Don't need anything fancy. The largest voltage range you will be dealing with is 12 volts. I have attached a convenient grounding post on the frame of my bike just for the voltmeter. Saves me from messing around with dodgy alligator clips hung on questionable bolts, that always fall apart at the penultimate moment.