It's like the meter assembly doesn't turn on when the bike turns on?
That sounds like maybe a ground is missing, but I don't think there's a separate ground for the lights as opposed to the meter panel.
The meter's connector is something you'd have had to remove the nose to get at, although connector C in the wiring diagram might be a candidate. I couldn't tell you where it is, probably right inside the frame behind the steering head, but there are only four wires in it, three of which go to the meter assembly. Thing is, the other one goes to the fuel injection relay, which obviously works.....
Connector A, with 14 wires, has a few to the meter, but also a lot of stuff other places on the bike, which if it was loose, the bike wouldn't run.