Ford Explorer Fuel Pump Relay Location: Find It Fast (Focus on 2011-2019 Models)

For owners of the fifth-generation Ford Explorer (model years 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, and 2019), the fuel pump relay is consistently located inside the Battery Junction Box (BJB), found near the vehicle’s battery under the hood. Look for the relay socket labeled #78 or #76, depending on the model year and engine configuration. This relay is crucial for powering the fuel pump; if it fails, your Explorer won't start.

Locating the fuel pump relay is a fundamental troubleshooting step when your Ford Explorer won't crank, crank but won't start, or the fuel pump makes no sound. While older generations vary, the placement within the engine bay's main power distribution center applies to the most common models on the road today. Identifying the correct relay quickly saves time and effort.

Understanding the Battery Junction Box (BJB)

The Battery Junction Box, often simply called the under-hood fuse box or fuse panel, is the primary power distribution center for your Explorer’s engine bay electronics. It's a large, usually black, plastic box housing numerous fuses and relays. On the 2011-2019 Explorer:

  1. Its Location: Open the hood. Look near the driver's side (for North American vehicles) by the firewall, mounted on a bracket close to the vehicle's battery. It's readily accessible.
  2. Accessing It: Removing the cover is straightforward. Lift the plastic clips securing the top cover. These clips require slight upward pressure to disengage. Once unclipped, lift the cover off entirely. Some models might have secondary sections; ensure you remove the main cover directly over the fuses and relays.
  3. Identifying the Relays: Inside, you'll see rows of mostly cube-shaped black or grey components. These are the relays. Fuses are smaller, often multi-colored, with visible wire elements inside. Relays are larger and blockier.

Identifying the Specific Fuel Pump Relay Socket (Positions #78 and #76)

The inside surface of the removed cover or a sticker mounted directly on the BJB itself contains a fuse and relay layout diagram. This diagram is your essential guide. It maps every slot, labeling them numerically.

  1. Finding #78: For the vast majority of 2011-2019 Ford Explorers, the primary fuel pump relay socket is labeled #78. Locate position #78 on the diagram. This spot is typically near the back corner of the junction box, relative to the vehicle's front. Match the diagram layout to the physical slots inside the box.
  2. When to Check #76: A few model year variations within this generation, or specific engine packages, might designate the fuel pump relay to socket #76 instead. ALWAYS CONSULT THE DIAGRAM FIRST. If #78 is not listed for the fuel pump but #76 is present in the box, check position #76 as per the diagram instructions for your specific vehicle. Never rely solely on online information over the diagram physically inside your hood.
  3. Physical Inspection: The relay socket itself is a plastic base with electrical connectors. The relay plugs into this socket. The relay often has its own numerical markings molded into the top surface (like "F8UO-14B192-AA" or similar). The key is knowing which socket the relay belongs in, based on the diagram.

What About Older Ford Explorers?

While the 2011-2019 generation dominates searches, understanding older locations is helpful:

  1. First Generation (1991-1994): Located in the Central Junction Box (CJB), inside the passenger cabin below the steering wheel, often near the hood release. Positions vary (e.g., slot C228 in the CJB for some years). Crucially, consult the under-dash diagram.
  2. Second Generation (1995-2001): Also located in the under-dash Central Junction Box (CJB). Finding the diagram inside the cover or inside the driver's kick panel is essential. Position numbers differ significantly.
  3. Third Generation (2002-2005): The fuel pump relay moved back under the hood for this generation. Find the Power Distribution Box (PDB) (sometimes called BJB), located near the battery, similar to the newer models. Check the diagram on the cover. Common positions include #103 or #203, but verifying is non-negotiable.
  4. Fourth Generation (2006-2010): Again, within the under-hood Power Distribution Box (PDB/BJB) near the battery. Relies heavily on the printed diagram inside the cover. Positions like #3.13 or #R201 might be used, but the diagram is paramount.

The constant thread with older models is the absolute necessity of consulting the fuse box diagram specific to that vehicle. There is no universal position across all model years before 2011.

Before You Touch the Relay: Safety & Diagnosis

Don't just pull the relay immediately. Follow basic safety and diagnostic checks:

  1. Battery Connection: Ensure the battery terminals are clean and tight. A loose or corroded terminal causes many electrical issues mimicking relay failure. Inspect the ground connections near the battery too.
  2. Listen for the Fuel Pump: Turn the ignition key to the "ON" position (but don't start the engine). Listen carefully from near the rear seats or fuel filler door. You should hear a distinct humming or buzzing sound from the rear fuel tank area for 1-2 seconds. This is the fuel pump priming. No sound is a strong indicator of an issue with the pump circuit – relay, fuse, pump itself, or wiring.
  3. Check the Fuel Pump Fuse: In the same under-hood Battery Junction Box (BJB), find the fuse associated with the fuel pump. Consult the diagram! Common labels include "Fuel Pump" or "FP". On 2011-2019 models, it might be fuse #F60 or #F67. Visually inspect the metal strip inside the fuse. A broken or melted strip means a blown fuse. Replace it with one of the exact same amperage rating (e.g., 15A, 20A). A blown fuse indicates a problem downstream (like a failing pump or wiring short) that caused it to blow. If the new fuse blows again, diagnose the underlying cause before focusing solely on the relay.

Testing the Ford Explorer Fuel Pump Relay

Replacing the relay is simple, but verifying it's actually faulty is wise:

  1. Swap Method: Find another relay in the BJB that has the exact same part number printed on top as your suspected fuel pump relay. Common relay positions to swap with include headlights, horn, blower motor relay, or starter relay – consult the diagram to find an identical relay. Swapping with the horn relay is often a simple test. Swap their positions. If your Explorer now starts (and the horn stops working), you've confirmed the original fuel pump relay was bad. Replace it.
  2. Listen for the Click: With the ignition turned ON, have a helper gently place their finger on the suspected relay. Feel for a distinct "click" when the ignition is cycled. Feel the relays nearby – if others click but the fuel pump one doesn't, it points to failure. You might also hear a faint click if the relay is activating but can't carry the full load.
  3. Electronic Test: Requires a basic multimeter. With the relay removed, test continuity between its high-power switching terminals (often labeled 30 and 87 on the bottom socket pattern) with the multimeter set to resistance or continuity. There should be NO continuity. Apply 12V power (or use jumpers from the battery) to the relay’s control coil terminals (typically 85 and 86 – consult the relay pinout or vehicle diagram). You should hear an audible click. While power is applied to 85 and 86, retest continuity between 30 and 87. There should now be CONTINUITY. If any of these conditions fail (no click, no continuity change), the relay is defective.

How to Replace the Ford Explorer Fuel Pump Relay

Replacement is straightforward once located:

  1. Ignition Off: Ensure the ignition is completely off.
  2. Remove Old Relay: Grasp the relay firmly. It pulls straight upward out of its socket. There are no latches. It requires moderate pulling force but be careful not to damage surrounding fuses.
  3. Match the New Relay: Crucially, use a relay with the EXACT same part number as the original. Using an incorrect relay can cause damage or malfunction. They are inexpensive and readily available from Ford dealers, auto parts stores, or reputable online retailers. A standard 4-pin automotive ISO mini relay is typically used, but verify the part number on the original.
  4. Install New Relay: Orient the new relay correctly. Look at the pin pattern on the bottom of the relay and match it to the socket. There are usually guides or differing pin sizes to ensure it can only go in one way. Press down firmly until it seats fully in the socket with a definite click.
  5. Test: Turn the ignition ON and listen for the fuel pump priming sound. Attempt to start the engine. If it starts, you've successfully solved the problem.

If Replacement Doesn't Work: Next Steps

If replacing the relay doesn't fix the issue, consider these possibilities:

  1. Faulty New Relay: Even new parts can be defective. Try another new relay if possible. Test the original and new relay using the swap method with a known good relay elsewhere in the BJB.
  2. Wiring Issues: Corrosion or damage in the wiring harness connecting the BJB to the fuel pump or the relay control circuit (from the PCM) can cause failure. Inspect visually for obvious damage near connectors or pinch points.
  3. Fuel Pump Failure: A completely dead fuel pump won't run even with a good relay and fuse. Test for power at the fuel pump harness connector during prime/start using a multimeter or test light.
  4. Inertia Switch Activation: Most Fords have an inertia safety switch that cuts power to the fuel pump during an impact. It can sometimes trip during rough driving or by mistake. Its location varies (under dash kick panel, passenger side kick panel, or trunk area) – check your owner's manual. It has a prominent button to reset it. Press the reset button firmly. Listen for the pump prime again.
  5. Bad PCM Control: The Powertrain Control Module commands the relay to switch. A failure in the PCM relay control circuit is less common but possible. Requires deeper diagnosis.

Finding Ford Explorer Relay Location Summarized

For the most common generation:

  • Model Years: 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
  • Location: Under the Hood in the Battery Junction Box (BJB) near the vehicle's battery.
  • Method: Remove the plastic BJB cover. Consult the fuse/relay layout diagram inside the cover or on the BJB. Look for the relay socket labeled #78 or occasionally #76. Match the diagram to the physical layout.
  • Confirmation: Compare position with the vehicle's specific diagram.

For older Explorers, prioritize checking the diagram inside the applicable fuse box (under-hood PDB/BJB for 2002-2010, under-dash CJB for 1991-2001). When in doubt, the printed diagram inside your specific vehicle's fuse box cover is the ultimate guide. Knowing where to look empowers you to diagnose and often resolve a common reason your Explorer won't start.

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