hi all 3 gens , can you please advise on following, fuel guage reads full on first start up , when only half a tank , after an hour or so goes back to normal , what position should the fuel guage sit with ignition off ? , or battery disconnected , if sender wire was grounded or disconnected what is it likely to read , trying to determine whether guage or sender playing up , any advise would be appreciated , thanks , luke , from all the way down under,