However, there isn't a single "fuel pump relay." The 7.3L's fuel system is controlled indirectly through several circuits and relays within the PDB. You'll need to consult your owner's manual or a wiring diagram to identify the specific relay(s) involved. These often control the fuel pump through the PCM (Powertrain Control Module).
To find the relevant relay(s):
1. Consult your owner's manual: It should have a diagram of the Power Distribution Box showing the location and function of each relay and fuse.
2. Use a wiring diagram: A wiring diagram specific to your year and model will show you the exact circuit for the fuel pump and which relay(s) are involved. You can find these diagrams online through forums dedicated to the 7.3L Power Stroke or from repair manuals.
3. Test the circuits: If you are comfortable working with automotive electrical systems, you can use a multimeter to test the power and ground going to the fuel pump. This can help pinpoint which circuit isn't working, guiding you towards the correct relay in the PDB.
Important Note: Before working on the electrical system, disconnect the negative battery cable to prevent accidental shorts or damage. If you're not comfortable working with automotive electrical systems, it's best to take your truck to a qualified mechanic.
