Where Is the Fuel Pump Relay on a 2003 F-150?

by Kyle McBride

Ford uses a fuel pump relay to control the fuel pump assembly in its 2003 F-150 series trucks. The relay receives low amperage battery voltage through the powertrain control module, which energizes the primary windings in the fuel pump relay and closes the normally open circuit in the relay. Higher amperage battery voltage is sent through the fuel pump relay to the fuel pump assembly located in the fuel tank. Excessive heat, high use, vibration and age can cause the fuel pump relay to fail. Locate and replace the fuel pump relay without special tools or procedures.

Step 1

Disconnect the negative battery cable, using a wrench.

Step 2

Identify the power distribution box in the engine compartment between the brake master cylinder and the inner fender well on the driver’s side. Remove the PDB cover.

Step 3

Locate the fuel pump relay in full relay slot 301. Grasp the fuel pump relay and pull it out.

Step 4

Plug the new fuel pump relay into the slot. Make certain that the relay is fully seated in the slot. Snap the PDB cover in place.

Reconnect the negative battery cable, using a wrench.


  • Disconnecting the battery will cause the vehicle to lose its adaptive driving strategy. Drive the vehicle for a short distance to allow the F-150 to relearn its adaptive driving strategy.
  • For an F-150 with the supercharged engine, the fuel pump hi-lo relay is located in slot 305 for Step 3.


  • Do not attempt to change any high-amperage relays without first disconnecting the negative battery cable.
  • Do not reconnect the battery negative cable unless the PDB cover is in place. Failure to comply can result in serious injury and damage to electrical components.

Items you will need

  • Wrench set

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