Looking at the schematic, all power goes thru the Main 30A fuse. The one by the battery. One feed goes to the turn signals, another to the ECU, and the third feed off the Main 30A fuse goes into the Junction Box. You need to verify you have 12v at all 3 of these locations. The .pdf is kinda shitty when it comes to wire identification.
Looks like at the Junction Box it's a Y/R possibly, which is the same color coming from the Main 30A.
The second wire off the Main 30A is BK/Y maybe, which remains the same color tapping several items, but notably your Front and Rear Blinkers. Your Fuel Pump, Fuel Level Sensor, Left Handlebar Switches, Headlight Relays (Low and Hi), and your Meter Assembly (guages) all run off this second feed. There are a couple grounds on this feed as well. One goes back to battery ground, other to frame ground.
The third wire off the Main 30A looks like it might be Y (or R). This one feeds your ECU, Regulator/Rectifier, Junction Box, Meter Assembly (guages), and Ignition Switch, where it branches in with both original color and Y/BK maybe after the plug (same color prior to the plug)
Since you have blinkers, I would assume you have both ignition and 12 past the Main 30A. There are several diodes in the path inside that Junction Box (I think there are some in the battery tray as well, don't remember) that could be bad. You need to trace all of these connections and find where you are losing power, and this will be your issue. Test before and after each component and when you don't have an after, there be your issue. If you can read a schematic, it will make more sense to you most likely than this explanation...
Trace the wires my man. You'll find the fault then. You ain't getting power to your cluster, and maybe not to the ECU either. It is getting to the ignition switch, and past it, because the blinkers work. Narrows it down a bit.