Fuel Gauge Not Working

My fuel gauge in my 99 didn’t work for a while and my pump went out recently and i changed the whole sending unit. The gauge worked for a few days and then it stopped working again i’ve checked the wiring at the plug but not at the top of the unit or in the tank. Could it be the sending unit again? Or something else like the computer. Sometimes the gauge will show a full tank and go down fast and gets to around 1/2 and the low fuel light kicks on and at about 1/8 or so the gauge drops out below E