To check the neutral switch: located at the back of the engine.
Disconnect the connector
Bike in neutral
Ignition ON, light should be off, if on the lead between the connector and the instrument panel must be earthing somewhere
Check continuity between the switch terminal and the crankcase, with the bike in neutral, there should be continuity. in gear there should be no continuity. If not check the switch plunger
If the switch is good, check thw wiring check wiring between the connector/starter circuit cut off relay/instrument cluster
Check for battery voltage at the light green terminal on the cut off relay side of the instrument cluster wiring connector with the ignition ON. If no voltage there, check continuity between the connector and the ignition fuse