The fuel pump on a 1989 Grand Marquis is located inside the fuel tank. To access the fuel pump, you must remove the back seat of the car, then unscrew the metal access plate which is mounted into the floor of the trunk.
Once you remove the access plate, you will be able to see the fuel pump. It is attached to the fuel tank by a rubber hose. To remove the fuel pump, simply disconnect the rubber hose and unscrew the fuel pump from the tank.
