Chrysler Repair: 1996 Neon Fuel Gauge, side kick panel, variable resistor

Question
1996 Neon fuel gauge works fine when tank is filled.  As fuel level drops, level indicated on fuel gauge drops very quickly.  When tank is approximately half full, gauge shows tank is empty.  Any suggestions on what to check first?

Thanks
Steve

Answer
P.S. That dark blue wire may very well be accessible at the plug in for the body control module which is usually mounted above the passenger side kick panel*, to the right of the passenger's right shin and up on the inner cowl. That unit has one or more multi pin plugs, (on the Cirrus it is on pin 15 of a 20-pin plug). You can simply remove the plug and measure the resistance from the dark blue wire's pin to ground (any shiney metal surface of the body).
Roland
*The body control module may actually be located right next to the fuse box in the cabin rather than where I suggested, above. I know very little about the Neon, unfortunately.



Hi Steve,
I think it is more likely that the sensor in the tank is flakey than that the gauge in the dash is bad. You can verify that by checking the resistance reading to ground of the pin for the dark blue wire which I believe you will find at the gas tank where both the power for the pump and the level are connected thru a 2- or3-pin plug. I could be wrong about the Neon for which I don't have a wiring diagram but am rather using the '96 Cirrus/Stratus diagram that I have. The sensor is a variable resistor (usually some sort of a sliding contact on a wound wire) and so if the contact is not made with the wire it goes infinite which results in a "empty" reading. It could be just a transient situation and the gauge might read normally if you let the fuel run down lower. In any case, if you verify that the resistance is infinite on that wire when the gauge has dropped to E, (and conversely that it reads a finite resistance when the tank if full) then it pretty much dictates pulling the pump and sender unit as a whole and replacing the sender part.
That is my best guess.
Roland