Could anyone help with a problem I am having with a fuel sensor. I have determined the fuel guage is good and working. Coming of the sensor are two wires a pink wire which is the sensor wire and a black wire which is the ground. I have the ground wire disconnected from the guage and have read articles that state if thats the case the guage would read empty. It reads about half full weather the ground is connected or not. I dont know where to go from here unless it could only be the sensor being bad but I still dont understand why if the ground is disconnected the guage would still show a reading off half full and not empty.
The Gauges work on a variable resistance principle. When you disconnect the ground, you open the circuit, which gives a infinite resistance reading to the sender. The gauge will do what it is designed to show, with only power and ground connected. This assumes that the tank is not grounded elsewhere (fuel fill?)
Pull out the sender and test it with an ohm meter. I think the range is something line 75-225 ohms from full to empty.
When I run into this problem, I usually disconnect both wires from the sender . Pull the sender out and away from the fuel tank. I then hook the two wires
back to the sender and turn the key switch on for power. Manually move the float with your hands while looking at the gauge. If it is a working sender you should see the movement register on the fuel guage . You have to know for sure your fuel gauge is working properly first. If the gauge is working properly, this should work. If the sender and the gauge is in good working condition, you may have bad wiring, between the two implements.