Reply to thread

Message: <blockquote data-quote="fortworth-cowboy" data-source="post: 142602" data-attributes="member: 27363">The ohm changes inside the sending unit, the controller measures the resistance and that is what shows the fuel level. If you just unplug a wire, it will throw a code, either fuel sending unit output high or low. But that does not diag the issue. What I usually always did, in the Bobcat Shop, I had an old but still good sending unit, unplugged the unit inside the machine and hooked my tester up to it. That way I was testing the wiring, the sending unit and the gauges. I have to say, that by these old T300 the displays often also go out.But without tester , I would remove the sending unit from the machine, leave it hooked up to the connector, turn the machine on ACC and watch the gauges while you move the swimmer up and down.In the case of PhilB here i suspect that the fuel sending unit is bent, thats why the swimmer stays up and always shows full. Usually the swimmer falls apart  or so and fills full with diesel and shows then always empty.</blockquote>