The fuel pump relay location on a 1993 Ford Mustang 4-cylinder is
in the Power Distribution Box (PDB), also known as the fuse box under the hood. It's not a standalone relay easily identifiable by labeling like some cars. You'll need to consult your owner's manual or a wiring diagram to pinpoint the exact location within the PDB. The diagram will show the relay's position and often include a legend identifying the relay for the fuel pump.
Unfortunately, without a wiring diagram specific to your 1993 4-cylinder Mustang, I can't give you a more precise location. Many online auto parts stores offer free wiring diagrams for download if you enter your vehicle's information.
