This procedure covers the removal and replacement of a relay in the main power distribution box or auxiliary fuse panel on a 2011-2014 Ford F-150 with the 3.5L EcoBoost engine.

Warnings

Tools required

Parts

• Replacement relay × 1 — Match amperage and terminal configuration to original relay

Preparation

1. Turn ignition off and remove key from vehicle
2. Identify which relay needs replacement by consulting owner's manual fuse/relay diagram or lid diagram on power distribution box
3. Note the relay location number and amperage rating
4. If working on relays controlling modules that store fault codes, consider disconnecting negative battery terminal to prevent phantom codes

Procedure

1. 1

   Access the relay box
   For engine compartment relays: Release the locking tabs on the power distribution box cover located near the battery on the driver's side. Lift cover off. For cab-mounted relays: Open the driver's door and locate the auxiliary fuse panel on the left side of the dash. Remove cover by pulling outward at the retention clips.
2. 2

   Locate the target relay
   Using the diagram on the underside of the cover or in the owner's manual, identify the specific relay position. Relays are typically larger than blade fuses and have 4 or 5 terminals. Note the orientation and any identifying markings on the relay body.
3. 3

   Remove the failed relay
   Grasp the relay body firmly and pull straight up with steady pressure. If the relay is stuck, use needle-nose pliers to grip the sides while pulling upward. Do not rock side-to-side as this can damage the socket terminals. Some relays may have a small tab that needs to be pressed before removal.
4. 4

   Inspect the relay socket
   Examine the socket terminals for corrosion, burning, or damage. Check for any melted plastic or discoloration which may indicate an overheating condition. If terminals appear damaged or corroded, clean with electrical contact cleaner and a small wire brush. Severe damage may require socket replacement by a qualified technician.
   ⚠If socket shows signs of melting or severe corrosion, investigate the root cause before installing new relay as the problem may recur
5. 5

   Verify replacement relay specifications
   Compare the replacement relay to the original. Verify matching amperage rating, terminal configuration, and physical dimensions. The relay should have the same number of terminals in the same positions. Installing an incorrect relay can cause electrical system damage or component failure.
6. 6

   Install the new relay
   Align the new relay with the socket, ensuring the terminals match the socket holes and any orientation key is properly positioned. Press the relay firmly and evenly into the socket until it is fully seated and flush with surrounding relays. The relay should click into place and should not sit higher than adjacent relays.
7. 7

   Reinstall the relay box cover
   Position the cover back onto the relay box, ensuring any locating tabs are properly aligned. Press down firmly on all corners until the locking tabs engage with an audible click. For cab-mounted panels, align the clips and push until seated flush with the dash.

Reassembly

1. If battery was disconnected, reconnect negative terminal and torque battery terminal bolt to specification
2. Ensure all covers are properly secured and latched to prevent water intrusion

Verification

• Turn ignition to ON position without starting engine and verify no warning lights indicate electrical faults
• Start the engine and verify the system controlled by the replaced relay is functioning properly
• Test all affected circuits (fuel pump, cooling fans, headlights, etc. depending on which relay was replaced)
• If replacing a fuel pump relay, verify engine starts and runs normally without stumbling
• Check for any diagnostic trouble codes using an OBD-II scanner if available

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