Fuel gauge not working 1991 RRC

I grew up in the southern parts of Namibia- still own farmland there. We have always used Land Rovers on the farm and various bodies and parts of chassis bear evidence of what they went through. I recall a '55 swb series 2 that was used with a "donkey" plough behind to lay a pipe line- 15 km in hard soil in low range for days on end.

Those Landies on the farm often had "optional" extras missing- like indicators, or wipers, or brake lights, or...a fuel gauge that's working.

Well my 91 RRC fuel gauge is not working as an "optional" extra...I simply write down when I fill up and then make sure I stop within 400 km to fill her up again.

But...perhaps someone out there knows how to fix this. What does "normally" go wrong? I have checked the fuse and connections. The warning light stays on. The needle is stuck.

Find the wire that sends the signal to the fuel gauge from the tank and connect it to earth.
Ignition on and if the gauge is working it will read full and that points to the sender unit itself which I think with yours is in combination with the in-tank fuel pump.

Thank you - (forgotten) old trick (reminder)!