hi all 3 geners , can anyone assist with the following , i have an erratic fuel guage , has been reading full when half a tank , after an hour or so returns to normal . not sure if sender unit or guage , where does guage normaly sit when ignition off ? , if sender wire is disconected where would it sit ? if it was grounded ? . any advise to ascertain whether guage or sender would be appreciated , cheers , luke , from all the way down under,

 

Grounding the sender wire should force the gauge to display empty. An open circuit should peg the gauge well above the full marking. 90Ω resistance should display precisely at the full mark.

Erratic indication can be the result of poor connections anywhere in the circuit, including the in-tank sender, tank ground and instrument panel connections.

 

Thanks vader for reply , I gather if sender unit , that means tank has to come out , not poss to acess from inside.?