2014 F150 Fuel Pump Relay Location: Your Essential Guide to Finding and Testing It

The fuel pump relay for a 2014 Ford F-150 is located inside the main engine compartment Power Distribution Box (PDB), specifically in position #35. Knowing this location is crucial if you're experiencing no-start issues or suspect a failing fuel pump. Acting as the electronic switch controlling power to the fuel pump, a faulty relay can leave your truck stranded. Locating and testing it is often the first practical step in diagnosing these problems.

Understanding the Power Distribution Box (PDB)

The Power Distribution Box is a large, rectangular, black plastic box situated in your truck's engine bay. It houses numerous fuses and relays responsible for protecting and controlling vital electrical circuits throughout the vehicle.

  1. Finding the PDB:
    • Open your truck's hood.
    • Look towards the rear of the engine compartment, near the firewall (the wall separating the engine bay from the passenger cabin).
    • For the vast majority of 2014 F-150 configurations (all cab styles - Regular, SuperCab, SuperCrew - and most engines), the PDB is located on the driver's side (left-hand side) near the firewall, specifically just behind the battery.
    • You will see a large, flat black lid covering the box. This lid needs to be removed to access the fuses and relays inside.

Pinpointing the Fuel Pump Relay (Position #35)

Once you have the PDB uncovered:

  1. Locate the Label: The inside of the Power Distribution Box lid is your primary resource. It features a detailed diagram showing the exact layout of every fuse and relay slot. If the lid diagram is faded or missing, carefully examine the top surface of the fuse box itself; Ford often molds the layout information directly into the plastic.
  2. Identify Position #35: Scan the diagram looking for the designation "#35". The diagram will clearly associate numbers with specific slots. Ford consistently uses slot #35 for the Fuel Pump Relay across the 2014 F-150 lineup.
  3. Relay Identification: Once you locate slot #35 in the physical box, look for a standard Ford-type ISO relay plugged into it. These relays are typically cube-shaped, roughly 1 inch per side, and are often black. They have four prongs or terminals on the bottom. Do not confuse it with larger fuses or different shaped components nearby. Compare it visually to other similar-looking relays in the box. Key identifiers are:
    • Slot number #35 on the diagram or box top.
    • Labeling on the diagram next to #35 usually says "Fuel Pump Relay" or something very similar like "FP" or "Fuel."
    • Its physical characteristics match the standard relay profile in the box.

What Does the Fuel Pump Relay Do?

Think of the relay as an electronically controlled heavy-duty switch. Here’s the process:

  1. Signal from the PCM: When you turn the ignition key to the "Run" position (or push the start button without braking for Keyless Start systems), the Powertrain Control Module (PCM) sends a relatively small electrical signal to the relay’s control circuit.
  2. Relay Activation: This small signal energizes an electromagnet coil inside the relay.
  3. Power Flow: The activated electromagnet pulls internal switch contacts together inside the relay. This action closes the high-power circuit that delivers full battery voltage directly to the fuel pump.
  4. Pump Runs: With power flowing through the closed relay contacts, the fuel pump activates, pressurizing the fuel rail and preparing the engine to start.
  5. After Start: The PCM continues to control the relay based on engine running status and various sensor inputs, keeping the pump running while the engine is operating. In certain safety situations (like an accident detected by inertia sensors), the PCM will deactivate the relay to stop the pump.

Symptoms of a Bad Fuel Pump Relay in Your 2014 F-150

Failure of the fuel pump relay usually results in a complete loss of power to the fuel pump. Common symptoms include:

  1. Engine Cranks But Won't Start: The starter turns the engine over normally, but the engine doesn't fire or run. This is the most classic sign. You might hear the starter spinning the engine but get no ignition sound at all.
  2. No Fuel Pump Prime Sound: When you turn the key to "Run" (before cranking), you normally hear a distinct whirring or humming sound for 2-3 seconds from the rear of the truck (where the fuel tank is). This is the fuel pump priming the system. If you hear no prime sound upon turning the key to "Run," a failed relay is a prime suspect. (Note: This test requires listening carefully).
  3. Sudden Engine Stalling: The engine stops running abruptly while driving, as if the key was turned off. It will then crank but not restart. This can also indicate a pump failure, but the relay should be checked first.
  4. Intermittent Starting Issues: You may experience no-starts sometimes, followed by normal starts other times. A failing relay with worn or corroded contacts can cause this erratic behavior. It might work when cold but fail when hot, or vice-versa.
  5. Relay Audible Click: Sometimes a completely failed relay might not make its characteristic faint "click" sound when the ignition is turned to "Run." However, hearing a click doesn't guarantee the relay is fully functional; its contacts might still be bad.

Testing the 2014 F150 Fuel Pump Relay

Before rushing to replace the relay, testing helps confirm it's faulty. Always observe safety first: Ensure the ignition is OFF and the key is removed (or Start/Stop button is off). Disconnecting the negative battery terminal is a good safety precaution.

  1. The "Swap Test" (Easiest & Recommended):

    • Locate another relay in the Power Distribution Box that is identical in size and shape to the #35 relay. Common choices include the Rear Window Defroster relay (#53), the Blower Motor relay (#71), or the Horn relay (#54). Crucially, consult the lid/fuse box diagram to find a relay that doesn't control a critical safety system and has the same part number. Never swap a relay controlling essential systems like the PCM or ignition.
    • Carefully pull the known good relay out of its socket.
    • Carefully pull the suspect fuel pump relay (#35) out of its socket.
    • Insert the known good relay into position #35. Ensure it's fully seated.
    • Turn the ignition key to the "Run" position. Listen for the fuel pump prime sound (2-3 second whir/hum from the rear).
    • If you now hear the prime sound and the truck starts (crank it to test), the original relay in #35 is faulty. If there's still no prime sound, the problem lies elsewhere (potentially the fuel pump itself, a fuse, wiring, or the PCM).
    • Remember to return the good relay to its original position afterwards.

  2. Listen for Relay Activation:

    • Have an assistant turn the ignition key to the "Run" position while you hold your fingers on the fuel pump relay in slot #35.
    • You should feel and potentially hear a faint but distinct "click" inside the relay when it activates. The absence of a click strongly suggests a problem with the relay or its control circuit. A click does not guarantee the power contacts inside the relay are making good connection; they could still be faulty.

  3. Visual Inspection (Limited Use):

    • While the relay is removed, inspect the terminals inside the relay socket (#35) in the PDB for any obvious signs of melting, burning, severe corrosion, or bent/damaged pins. Look for green or white crusty deposits.
    • Examine the relay's metal prongs/tabs. Are they clean, shiny, and free of corrosion or excessive carbon buildup (which looks like dark, pitted marks)? Significant corrosion or heat damage (discoloration/melting plastic) warrants replacement, but absence doesn't guarantee it's good.

  4. Multimeter Testing (For the Adventurous): Requires a digital multimeter (DMM). Testing involves checking for continuity across the high-power circuit contacts when the relay is activated. The exact pin configuration varies, and activating the coil safely requires a separate power source (like the truck's battery) and specific setup. Due to complexity and risk of incorrect diagnosis or damage, this method is generally less practical for the average DIYer than the simple swap test. Consult a vehicle-specific repair manual for the precise relay terminal layout and procedure if you insist on this method.

Replacing the Fuel Pump Relay in a 2014 F-150

If testing confirms the relay is faulty:

  1. Obtain the Correct Part: Ensure you get an exact replacement relay. Options:

    • Ford Dealership Parts Counter: Provides the guaranteed correct OEM part. Ask for "Fuel Pump Relay for a 2014 F-150". The OEM part number is typically something like DG9B-14B192-AA or 9L1Z-14B192-AA or 4C3Z-14B192-AA (confirm VIN or your old relay), but new supercessions may exist. Provide your VIN for accuracy.
    • Auto Parts Stores: Ask for a "2014 Ford F-150 fuel pump relay." Compare the new relay visually to your old one – shape, terminal layout, and amp rating (often printed on top, e.g., "20A," "30A") must match precisely. Bring your old relay to compare. Brands like Standard Motor Products (SMP), BWD, or Bosch are generally reliable.
    • Online Retailers: Ensure you search specifically for the 2014 F-150 application and verify compatibility. OEM or reputable aftermarket brands are best.

  2. Replace the Relay:

    • Ensure the ignition is OFF and the key is removed.
    • Disconnecting the negative battery terminal provides added safety.
    • Locate the old relay in the PDB (#35 slot).
    • Firmly grasp it with your fingers and pull straight up to remove it. No tools should be needed; excessive force risks damage.
    • Position the new relay correctly over the slot, matching the terminal layout (it usually only fits one way).
    • Press down firmly and evenly until it is fully seated. You should feel it click into place.
    • Reconnect the negative battery terminal if disconnected.
    • Turn the ignition to "Run" and listen for the fuel pump prime sound.
    • Attempt to start the engine. If successful, the replacement fixed the issue. If not, further diagnosis is needed.

Crucial Safety Precautions When Working with Fuel System Components

  • Fuel Vapors are Extremely Flammable: The fuel system is under pressure. Avoid sparks, open flames, and smoking anywhere near the vehicle while working, especially near the fuel tank or lines. Work in a well-ventilated area.
  • Relieve Fuel Pressure: Before disconnecting any significant fuel lines (though not strictly necessary for just the relay), the fuel pressure should be relieved. This involves steps like removing the fuel pump fuse/relay and running the engine until it stalls, but if you're only replacing the relay itself, this pressure relief is generally not required.
  • Battery Disconnection: Disconnecting the negative (-) battery cable is a simple safety step that prevents accidental short circuits while handling electrical components like the relay. Always disconnect negative first and reconnect it last.
  • Quality Parts: Use only high-quality OEM or reputable aftermarket relays. Cheap, unreliable relays can fail prematurely or even pose a fire risk.
  • Don't Force Anything: Relays should push in and pull out by hand without excessive force. If stuck, wiggle gently. Forcing it can break the relay or damage the socket.
  • Know Your Limits: If you are uncomfortable with electrical work or unsure about any steps, consult a qualified mechanic.

What If It's Not the Relay? Troubleshooting Next Steps

If you've confirmed the relay is good and properly seated (especially after a swap test), and your 2014 F-150 still has no fuel pump prime sound/no-start:

  1. Check Fuel Pump Fuse: Locate the fuel pump fuse in the Power Distribution Box. Refer to the lid diagram again. It's often labeled as "Fuel Pump" or "FP," typically rated for 20A or 25A. Common locations include slots like #27 (20A mini-fuse) or similar – always confirm with your diagram. Carefully pull it out and inspect the metal strip inside. If it's melted or broken (blown), replace it with a fuse of the exact same amperage. Note: A blown fuse often indicates an underlying problem like a short circuit in the fuel pump wiring or pump motor itself.
  2. Inertia Fuel Shutoff (IFS) Switch: The 2014 F-150 has a safety device called an inertia fuel shutoff (IFS) switch. If the vehicle experiences a significant jolt (like an accident or sometimes even a hard pothole), this switch is designed to trip and cut power to the fuel pump. It's usually located in the passenger footwell area, either behind/under the kick panel near the door or possibly high up near the center console. Consult your owner's manual for its exact location and reset procedure (typically involves pushing a reset button on the switch). Note: A tripped IFS switch is a common cause of sudden no-start/stall with no prime sound and is easy to check/reset. Ensure it hasn't tripped.
  3. Fuel Pump Driver Module (FPDM): Some models (less common on 2014) use a module instead of a simple relay. However, for the 2014 F-150, the primary control is the fuel pump relay. The FPDM is not applicable.
  4. Wiring Issues: Inspect wiring harnesses related to the fuel pump circuit for visible damage, chafing, corrosion (especially near connectors under the truck), or rodent chew marks. Pay attention to connections at the fuel pump itself (top of the fuel tank), at the relay/PCM, and the inertia switch.
  5. Faulty Fuel Pump: A completely failed fuel pump motor is a common cause of no prime/no-start. Confirming this often requires checking for voltage at the fuel pump connector (located near the fuel tank, often accessible by removing spare tire or bed liner) while the ignition is in "Run" (needs two people). You should see battery voltage present for 2-3 seconds. If voltage is confirmed but the pump doesn't run, the pump is faulty. Warning: Checking pump voltage involves safety risks due to exposed connectors; proceed with extreme caution.
  6. PCM Issues: Less common, but a problem with the PCM itself (corrupted software, internal fault, bad power/ground) could prevent it from signaling the fuel pump relay to activate. This requires professional diagnosis with specialized scan tools.

Conclusion: Pinpointing Relay #35 is the First Step

Knowing the precise 2014 F150 fuel pump relay location (Position #35 in the engine compartment Power Distribution Box) empowers you to tackle one of the most common causes of frustrating no-start situations. The simple swap test is an effective diagnostic tool, making it relatively easy to determine if the relay is the culprit before exploring more complex and expensive solutions like a fuel pump replacement. Always prioritize safety by disconnecting the battery and being mindful of flammable vapors. If the relay proves good or replacing it doesn't solve the problem, systematically checking fuses, the inertia switch, and wiring will guide your next steps, potentially saving you significant time and money.

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