Local repair shop replaced the fuel filler neck in my '99. Got it back and the fuel gauge was inop, showing empty. I called the shop and they didn't think anything from the neck replacement would result in temporary disabling of the fuel gauge, speculating the pump/sender unit might be on the fritz. Any thoughts are appreciated.

 

check the wires above the gas tank for anything frayed, broken, unplugged etc.

why did you need your filler neck replace?

 

This may help:
98+ Fuel Gauge Diagnosis