Fuel gage sender problem?

Hi,
I have a 93 XJ 4.0 and my fuel gage is reading Zero and the low fuel light is on, although the tank is almost full. Gage is on the stop and could not go any lower. Any ideas or clues where to start looking would be most welcome. Thanks

Go the tank.

Check for voltage for the gauge. Your ground should be Ok or you wouldn't have a working fuel pump.

If you have voltage for the gauge, then you will probably have to pull and test the sender's resistance values.