gas gauge not working?

Hello,

It sounds like the fuel pump sending unit might be faulty. There is a float attached to the fuel pump which goes up and down with the fuel level and transmits that to the gauge. Many times the connector for the float goes bad casing the fuel gauge to give incorrect reading.
On this vehicle that fuel sending unit is part of the pump. So the fuel pump assembly needs to be replaced in order to get the sending unit.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

https://youtu.be/D1AyqeftAmA

I have attached the replacement procedure for your reference.

Please let me know of any questions.

Thank you.