Just Installed A New Fuel Pump On 94 Dodge Dakota, Now The Gas Gauge Don't Work?

Sorry to tell you this but you are probably going to have to go back and re-do this job.

The sender for the gas gage is part of the fuel pump assembly. So it all has to come out to fix it.

The only easier possibility is that the wiring harness to the pump/sender is messed up. Then you will only have to remove the fuel tank to fix. :(