Posted: Thu Jun 19, 2003 11:40 am
The polarity should not make any difference, as my gauge read the right way when my car was positive earth, as it does now when negative earth.
The fuel gauge is basically a current meter, and reads empty when there is a small current passing, and full when a large current passes.
If you switch the connections on the back of the gauge it will try to read less than empty (i.e. the needle will try to go off the scale to the left).
The sender in the fuel tank is basically a variable resistor which earths the fuel gauge more and more, the fuller the tank gets, thus causing more current to flow and deflecting the gauge needle more.
a simple test for you to do is: disconnect the wire from the tank sender (on top of the tank) and the gauge should read empty. Then connect the wire to the body (shorting it out) and the gauge should read full. If this is the case, then you may have the wrong fuel sender with the variable resistor upside down.
Have a check, and let us know.......
The fuel gauge is basically a current meter, and reads empty when there is a small current passing, and full when a large current passes.
If you switch the connections on the back of the gauge it will try to read less than empty (i.e. the needle will try to go off the scale to the left).
The sender in the fuel tank is basically a variable resistor which earths the fuel gauge more and more, the fuller the tank gets, thus causing more current to flow and deflecting the gauge needle more.
a simple test for you to do is: disconnect the wire from the tank sender (on top of the tank) and the gauge should read empty. Then connect the wire to the body (shorting it out) and the gauge should read full. If this is the case, then you may have the wrong fuel sender with the variable resistor upside down.
Have a check, and let us know.......