BLue/YeLlow wire (not BK) on 5 prong starter relay. That's the wire that has no power but all the fuses are intact, so I'll investigate that more thoroughly.
Eng management relay shown in this diagram is 4 prong and that's what the bike has.
Update - after all that, it WAS the clutch switch. I'd removed it and its rubber cover a few days ago and cleaned the blackened contacts but apparently did not reassemble it correctly!!!