Oil & Fuel Fuel Gauge not functional

[Stormtruck2]

4600. Fuel gauge indicates almost full finally dropping to about 3/4s just as I run out of fuel. I replaced the sending unit and it still indicates the same. Anything besides a bad gauge to check? I hope its not a gauge, I believe that takes a whole new cluster to fix. Lots O dollars to do that.

 

[Johndeere3720]

4600. Fuel gauge indicates almost full finally dropping to about 3/4s just as I run out of fuel. I replaced the sending unit and it still indicates the same. Anything besides a bad gauge to check? I hope its not a gauge, I believe that takes a whole new cluster to fix. Lots O dollars to do that.

My dad's 3720 has the same problem. There is a sensor that indicates fuel level in the tank that is known to go out. It isnt cheap to fix, about $200 so my dad just looks in the tank periodically to see how much fuel it has. Yesterday I started up the tractor and the gauge read no fuel but when I started feeding with the tractor the gauge went up to full then back to half a tank. The sensor itself doesnt cost much, the $$ is when the mechanics have to replace it, an estimated 2 hour job.

 

[deputy11]

Found the way to see if it is the tank sensor or fuel guage that is bad for the 3520. Probably the same for 3720 but probably won't apply to a 4600 unless the empty tank vs full tank voltages would help. Since the fuel guage is part of the panel cluster it would be big $$$$.