Here's link to
NASA Wiring Manual. I think there'd be lots fewer plane-crashes if FAA adopted more stringent NASA wiring standards. Although more and more crashes are due to software glitches nowadays. Don't get me started on programmers...
There should be 2-wire connector on harness (right side) just under tank. It may not be visible unless you take tank off and look from top. This is for fuel-level sender. Make sure plug is connected to tank. I've seen senders fail as they are mechanical floats (like toilet). You can remove sender from tank and measure resistance between 2 terminals of plug. Then manually move sender float and see if resistance changes.
There's also strange vent-hose that goes under fuel-level sender. I suppose to drain gas & fumes down under bike if sender leaks. Don't want it dripping on hot engine.