2007 Ford Explorer Fuel Pump Relay Location: A Comprehensive Guide

The fuel pump relay in a 2007 Ford Explorer is located under the hood in the Battery Junction Box (BJB), often referred to as the main power distribution center. Look for a small, usually green or gray electrical component plugged into one of the relay sockets within this box.

If your 2007 Ford Explorer cranks but refuses to start, or if you hear no fuel pump humming when you turn the key to the "ON" position, the fuel pump relay is a prime suspect. Knowing its exact location is the crucial first step in diagnosing or replacing it. Located within the engine compartment for easy access, finding the relay is straightforward once you know where to look. This guide provides detailed, step-by-step instructions to locate, identify, test, and replace this critical component, helping you get your Explorer back on the road.

Understanding the Battery Junction Box (BJB)

The Battery Junction Box (BJB) is the central hub for numerous electrical components in your 2007 Ford Explorer. It houses a variety of fuses and relays that protect and control electrical circuits throughout the vehicle.

  • Location: It's situated in the engine compartment. The box is a rectangular, usually black plastic housing with a removable cover.
  • Finding It: Stand in front of your Explorer facing the engine. The BJB is mounted near the battery and the firewall (the wall separating the engine compartment from the passenger cabin). It is typically towards the passenger side (right side) of the vehicle, near the strut tower or attached directly to the inner fender wall. Some models may have it closer to the center.
  • Access: Open your hood and secure it with the prop rod. Locate the BJB. To open it, you'll need to release the latches holding the cover in place. These are usually clips on the sides that you squeeze or pull upwards simultaneously.

Identifying the Fuel Pump Relay Inside the BJB

Once you have the BJB cover removed, you'll see an array of fuses (smaller components with clear plastic tops showing colored blades or a wire element inside) and larger components called relays.

  • What Does a Relay Look Like? Relays are cube-shaped electrical components, typically measuring about 1 inch square. They have multiple prongs or terminals on the bottom that plug into sockets within the BJB. The top often has a diagram showing the internal circuit or numbering of the terminals. Common colors for Ford relays are green or gray, but the critical identifier is the relay's position and the diagram on the BJB cover.
  • Crucial Reference: The BJB Cover Diagram: The underside of the BJB cover is your absolute best guide. Flip the cover over. It will feature a detailed diagram or map listing every fuse and relay slot, clearly labeled with the circuit it protects or controls. Find the slot labeled "Fuel Pump Relay," "Fuel Pump," "FP," or "PCM Relay" (in some Ford designs, the PCM relay can be linked, but the Fuel Pump label is key). This label corresponds directly to a specific socket position within the junction box.
  • Fuel Pump Relay Position: Based on the diagram on your specific BJB cover, locate the identified slot. Compare the shape and pin configuration of the socket with the labels on the diagram to ensure accuracy. The relay itself might also have a number molded into its plastic housing (like a Ford part number such as F57B-14B192-AA, F65B-14B192-AA, or similar), but the socket position indicated by the cover diagram is the definitive method.
  • Example Location: In many 2007 Ford Explorer configurations, the fuel pump relay is found in Position #304 within the BJB. However, ALWAYS verify this using your specific cover diagram, as variations exist.

Symptoms of a Failing Fuel Pump Relay

Understanding the signs that point to a potential fuel pump relay issue helps in targeted troubleshooting. Common symptoms include:

  1. Engine Cranks But Won't Start: This is the hallmark symptom. The starter motor spins the engine, but it doesn't fire up because no fuel is reaching the engine.
  2. No Fuel Pump Prime Sound: When you turn the ignition key to the "ON" position (without cranking), you should hear a distinct humming or buzzing sound coming from the rear of the vehicle (near the fuel tank) for about 2-3 seconds. This is the fuel pump pressurizing the system. If you hear no sound at all during this key-on phase, a dead relay is a top suspect.
  3. Intermittent Starting Issues: The engine might sometimes start and sometimes not, or start only after multiple attempts. This can indicate a relay with failing internal contacts.
  4. Engine Stalling During Operation: A failing relay that cuts power while driving can cause the engine to suddenly shut off without warning.
  5. Relay Clicking Sound: Sometimes, you might hear the relay clicking rapidly under the dash or hood when trying to start the car, indicating it's trying unsuccessfully to engage.

How to Test the 2007 Ford Explorer Fuel Pump Relay (Simple Methods)

Before rushing to buy a new relay, testing the existing one is prudent. Here are practical methods:

  1. The Swapping Test (Best Method): This is often the easiest and most reliable approach without special tools.
    • Identify the fuel pump relay using the BJB cover diagram.
    • Look for another relay in the BJB that has the exact same part number or pattern diagram and is labeled for a non-critical circuit, such as the horn relay (often labeled "Horn"), blower motor relay ("Blower," "A/C," "HVAC"), or rear window defogger relay ("Defog"). Do NOT use relays critical for engine operation (like PCM relay) or safety systems (like ABS).
    • Carefully remove both the fuel pump relay and the identified matching relay. Note their original positions.
    • Install the known good relay (from the horn/etc. slot) into the fuel pump relay socket.
    • Turn the ignition key to "ON." Listen for the fuel pump priming sound (2-3 second buzz/hum).
    • If the pump now primes, the original fuel pump relay is faulty.
    • Try to start the engine (if priming worked).
    • Reinstall the original relay back into its slot and test the swapped circuit (e.g., honk the horn) to ensure it still works and the relay you used is indeed good.
    • Swap them back to original positions once testing is complete.
  2. Listening/Feeling Test:
    • Locate the relay and have an assistant turn the ignition key to the "ON" position.
    • Place your fingers on the relay. You should feel and usually hear a distinct "click" as the relay energizes when the key is turned on. If you feel nothing, the relay may not be receiving power or the internal coil has failed. However, a click doesn't guarantee the internal power-switching contacts are intact, but a lack of click is a strong indicator the relay coil isn't working or isn't getting a signal.
  3. Simple Circuit Test with a Test Light/Multimeter (Requires Basic Tools & Caution):
    • Caution: Be careful not to short any terminals. Use appropriate settings.
    • Locate the Relay and Diagram: Identify the fuel pump relay and its socket. Look for a diagram on the relay itself (usually the terminals are numbered like 85, 86, 30, 87, sometimes 87a).
    • Understanding the Terminals: For a standard 5-pin relay (most common):
      • Terminals 85 & 86: Coil control circuit (where a small signal tells the relay to turn on).
      • Terminal 30: Common power input from the battery (usually fused).
      • Terminal 87: Normally open contact – outputs power to the device (fuel pump) when the relay is energized.
      • Terminal 87a: Normally closed contact (usually not used in fuel pump circuits in this vehicle).
    • Testing for Coil Activation Signal:
      • Use a test light or multimeter set to DC Volts (20V range).
      • With the relay plugged in, probe Terminal 86 (or Terminal 85) relative to a good ground point (like unpainted metal on the chassis).
      • Have an assistant turn the key to "ON." You should see voltage appear briefly (approximately 12 volts) for the 2-3 seconds the pump primes on the terminal you probe (if you probe the coil ground terminal, you'd see ground/0V appear when activated, but voltage testing the hot side is more common). No voltage suggests a problem with the activation circuit (PCM issue, fuse, wiring).
      • If voltage appears on the coil terminal during "key on," it means the PCM is sending the signal. Proceed to output test.
    • Testing Output Power (Terminal 87):
      • Probe Terminal 87 in the relay socket relative to ground.
      • Have an assistant turn the key to "ON." You should see approximately 12 volts appear at Terminal 87 for the duration of the priming cycle. If voltage appears at the socket Terminal 87 during "key on," it strongly indicates the issue is downstream (pump wiring, pump itself). If no voltage appears at Terminal 87 when the relay should be energized (and you know the coil is getting signal), the problem likely lies within the relay contacts or the input power to Terminal 30.
    • Testing Relay Bench Function: (Safest with relay removed).
      • Use a multimeter set to resistance (Ohms) or continuity (beep mode).
      • Between Terminals 30 and 87: There should be NO continuity when the relay is de-energized (at rest).
      • Apply 12 volts to Terminals 85 (hot) and 86 (ground) – you can use jumper wires to a battery or a 9V battery may suffice (click confirms coil works). Be careful not to touch terminals.
      • While applying voltage to the coil, check between Terminals 30 and 87. There should now be continuity (or very low resistance). Continuity confirms the internal switch contacts close correctly.
      • If the relay fails any of these steps, it is defective.

How to Replace the 2007 Ford Explorer Fuel Pump Relay

Once you've confirmed the relay is faulty, replacement is simple:

  1. Gather Supplies: Purchase the correct replacement relay. You have options:
    • Ford OEM Relay: Obtain the relay by its Ford part number (e.g., F57B-14B192-AA, F65B-14B192-AA, etc.). You can find this number printed on the old relay itself or from the BJB diagram/owner's manual supplement or Ford dealer parts department. This ensures exact compatibility. Sometimes parts stores cross-reference these numbers.
    • Auto Parts Store Relay: Take the old relay to any major auto parts store. They can match it by appearance and the standard industry number(s) often printed on it (like "JD1912," "RY449," "WIGG32" - these are interchange numbers). Show them where it was located. Ensure the terminal pattern and any internal diode/resistor match the original.
    • Universal Relay: Be cautious. While universal relays matching the terminal pattern may physically fit, they might not have the necessary internal suppression components. Stick with a relay specifically listed as compatible with your Explorer to avoid electrical noise issues or premature failure.
  2. Locate and Access the Relay:
    • Park your Explorer on a level surface, engage the parking brake, and open the hood.
    • Locate the Battery Junction Box (BJB) near the battery/firewall on the passenger side.
    • Open the BJB cover by releasing the clips. Set the cover aside safely.
    • Identify the fuel pump relay position using the diagram on the cover or your previous identification.
  3. Removing the Old Relay:
    • Grasp the relay firmly. It should be seated vertically in its socket.
    • Pull it straight up. It might require some initial force if it's been in place for years. Avoid excessive side-to-side rocking which could damage the socket.
    • If it's extremely tight, carefully use needle-nose pliers, gripping the relay body as low as possible without touching the terminals. Apply even upward pressure.
  4. Installing the New Relay:
    • Take the new relay and orient it so the terminal pattern matches the socket. Most sockets have a guide notch or key way, and the relay will only go in one way. Do not force it.
    • Align the relay's terminals over the socket holes.
    • Push the relay straight down firmly until it seats fully. You should feel it click or bottom out.
    • Visually confirm it's seated flush and securely.
  5. Verification:
    • Close the BJB cover securely.
    • Turn the ignition key to the "ON" position. You should now hear the fuel pump prime for a few seconds.
    • Attempt to start the engine. It should start normally if the relay was the only issue.
    • If it doesn't start, double-check the relay installation position and revisit potential other causes.

Important Considerations and Compatibility

  1. 2007 Model Year Variation: While this guide covers the vast majority of 2007 Ford Explorers, very late-build 2007 models, especially those with options related to auxiliary power or different trim levels, might sometimes have variations. Always, always refer to the diagram on your specific Battery Junction Box cover first. That diagram is the ultimate authority for your vehicle. If your diagram differs significantly, trace the "Fuel Pump Relay" label.
  2. Relay Compatibility: Not all relays are created equal. Using a relay with the wrong pin configuration or lacking internal diodes can cause malfunctions or damage to other sensitive electronics like the Powertrain Control Module (PCM). Using the Ford part number or a store interchange relay based on your old relay is the safest bet. Avoid generic "looks similar" relays.
  3. Fuse Connection: The fuel pump circuit has at least one main fuse protecting it. This fuse is also located in the BJB. If a relay swap/test indicates the relay itself is working, check the relevant fuse(s). A blown fuse could indicate a short circuit elsewhere (like a failing pump). The diagram on the BJB cover will show the Fuel Pump Fuse position (e.g., often labeled Fuse # 41, Fuse # 108, etc., rated for 15A, 20A, or 30A – check diagram).
  4. Not the Fuel Pump Itself: While a bad relay mimics many symptoms of a failed fuel pump, you should rule out the relay (via swapping or testing) before considering the much harder and more expensive task of replacing the fuel pump itself. If replacing the relay solves the problem for a short time and then it recurs, it could indicate an issue causing relay failure (like wiring problems drawing too much current) or a sign the fuel pump itself is becoming overloaded and might be failing.

Troubleshooting if a New Relay Doesn't Solve the Problem

If you've replaced the relay with a known good unit and the fuel pump still won't activate, the problem lies elsewhere in the fuel delivery system:

  1. Check Related Fuses: Verify the main fuse for the fuel pump (located in the BJB, see diagram) is intact. Also check the PCM Power Relay fuse and fuse, and the PCM relay itself, as a dead PCM won't command the fuel pump relay to activate.
  2. Inertia Fuel Shutoff (IFS) Switch: Ford vehicles have a safety switch designed to cut fuel pump power in the event of a significant impact. It's usually located in the passenger footwell area (kick panel near the center console or under the glove box). Sometimes it can be tripped by a sharp bump. Find it (refer to your vehicle's manual for precise location and reset procedure), inspect it for tripping, and press the reset button firmly. Listen for a click.
  3. Fuel Pump Wiring: Inspect wiring from the relay socket (Terminal 87) back to the fuel pump at the tank for visible damage, corrosion, or disconnection, especially near connectors under the vehicle. Checking for voltage at the fuel pump connector (located near the fuel tank) with the key on is a definitive test, but accessing it requires lifting the vehicle safely.
  4. Fuel Pump Failure: If the relay has power going in, gets a proper activation signal, sends power out (voltage at Terminal 87 socket when key is ON), and the fuse is good, yet there's no power at the fuel pump connector, the wiring between the BJB and the pump is suspect. If power does reach the pump connector but the pump doesn't run, the fuel pump itself is likely defective.
  5. PCM Control Issue: The Powertrain Control Module (PCM) is the brain that sends the ground signal to the relay coil (Terminal 85) to activate it. If the PCM isn't getting power itself (check PCM fuse and PCM Power Relay in the BJB), or has a fault, or doesn't sense the correct conditions (like valid security system/immobilizer signal, Park/Neutral switch engaged), it will not command the fuel pump to run. This requires deeper diagnostic scanning tools.

Tools You Might Need (Simple Job)

  • Your hands
  • Replacement fuel pump relay (correct part number/interchange)
  • Needle-nose pliers (optional, if relay is stubborn)
  • Shop manual or reference for your specific vehicle (optional, diagram on BJB cover is primary source)
  • For testing: Test light or multimeter (optional but helpful), Jumper wires (optional for bench testing).

Safety Precautions

  • Always work with the vehicle parked, parking brake engaged, and the ignition off and key removed before opening the BJB or handling relays.
  • Avoid shorting relay socket terminals with metal tools.
  • Handle electrical components carefully. Avoid static discharge by touching bare metal on the chassis before handling relays.
  • Use caution when lifting the hood and around moving engine parts (even though engine will be off).
  • The fuel system operates under pressure. Never work on fuel lines near the tank without properly depressurizing the system via the fuel rail test port or by waiting several hours after turning off the engine. This guide deals only with the relay.

Conclusion

Locating the fuel pump relay in your 2007 Ford Explorer is a simple task when you know it resides in the Battery Junction Box (BJB) under the hood. By carefully consulting the diagram printed on the underside of the BJB cover, you can pinpoint its exact socket location. Armed with this knowledge, you can effectively test the relay using methods like swapping with an identical component, listen for the activation click, or perform basic voltage checks. Replacing a faulty relay is generally a quick, affordable, and easy fix that can resolve no-start or no-fuel-pump issues. Remember to use the correct replacement part and double-check the fuse while troubleshooting. Should replacing the relay not solve the problem, you'll then need to investigate other potential causes like the inertia switch, fuel pump fuse, or wiring issues downstream towards the fuel pump itself. Knowing the 2007 Ford Explorer fuel pump relay location empowers you to perform this essential first step in diagnosing common fuel delivery problems.

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