Why is 2001 Mazda b3000 fuel gauge stuck on full after installing new fuel pump?

If the fuel gauge on a 2001 Mazda B3000 is stuck on full after replacing the fuel pump, it could be due to a few reasons. One possibility is that the fuel level sending unit, which measures the fuel level in the tank, may not be properly connected or could be faulty. Additionally, there could be a wiring issue or a problem with the gauge itself. It's also worth checking for any debris or damage in the tank that might be affecting the sending unit's operation.