1999 Ford Explorer Fuel Pump Fuse Location: A Comprehensive Guide

The fuel pump fuse in a 1999 Ford Explorer is located in the engine compartment's Power Distribution Box (PDB), specifically identified as Fuse #4 (a 15 Amp fuse).

Locating the correct fuse for your 1999 Explorer's fuel pump is crucial when troubleshooting no-start, sputtering, or fuel delivery issues. Using the wrong fuse location or an incorrect amperage replacement can lead to continued problems or electrical damage. Here’s exactly where to look and what to do.

1. Identifying the Power Distribution Box (PDB)

The primary fuse box for the fuel pump circuit in your 1999 Explorer is the Power Distribution Box (PDB), located in the engine compartment. It's a large, black, rectangular or square plastic box. It's much larger than the fuse panel inside the vehicle cabin. You will find it positioned near the driver's side fender wall (left front side of the engine bay, closest to the brake master cylinder).

The PDB has a lid secured by clips. Lift this lid straight up to remove it. You should see numerous fuses, relays, and possibly a diagram printed on the underside of the lid. This diagram is your primary map. Always locate the diagram first.

2. Pinpointing Fuse #4 (15A)

Refer to the diagram on the underside of the PDB lid. Look for the fuse labeled:

  • "F/PUMP" (or sometimes "Fuel Pump"), Fuse #4, 15A.
  • Sometimes the labeling might simply read "F/P" or "FP".

Fuse #4 is typically located in the front row or near the front of the Power Distribution Box when facing it from the front of the vehicle. Physically, it will be a standard mini blade fuse, colored blue (15A is the standard color code).

3. Secondary Fuse Location: The Underhood Fuse & Relay Center (Some Models)

While the PDB (#4 fuse) is the primary location, Ford documentation sometimes refers to an "Underhood Fuse & Relay Center." For the 1999 Explorer, this is one and the same as the Power Distribution Box described above. There is no secondary underhood fuse panel distinct from the PDB for the fuel pump fuse. Confusion sometimes arises from online diagrams mislabeled for other Ford vehicles; the PDB is your target.

4. Related Component: The Fuel Pump Relay

Often searched for alongside the fuse, the fuel pump relay is also located within the Power Distribution Box (PDB). Consult the lid diagram to find its specific slot. A common location in the 1999 Explorer PDB is:

  • Relay # 202 (or just labeled "Fuel Pump" or "FP").
    It's a standard black automotive cube relay, usually plugged into a socket holding 4 or 5 terminals.

5. Steps To Inspect and Replace the Fuel Pump Fuse

  1. Safety First: Park the vehicle on a level surface. Turn the ignition OFF. Engage the parking brake. Disconnect the negative battery terminal. This is critical to prevent sparks near the fuel system components and protect the electrical circuits.
  2. Locate PDB: Open the hood. Find the Power Distribution Box near the driver's side fender wall.
  3. Remove PDB Lid: Unclip and lift off the lid. Store it safely.
  4. Identify Fuse #4: Consult the diagram on the underside of the lid. Find the fuse labeled for the Fuel Pump (F/PUMP or equivalent), identified as Fuse #4, 15A.
  5. Remove the Fuse: Use a fuse puller tool (often included in the PDB lid) or needle-nose pliers with extreme care. Grasp the fuse firmly and pull straight up.
  6. Inspect the Fuse: Hold the fuse up to the light. Look at the metal strip inside the colored plastic housing. If the strip is broken, melted, or has a visible gap, the fuse is blown. If the strip looks intact and connected at both ends, the fuse is likely good.
  7. Test for Power (Optional but Recommended): If you have a digital multimeter (DMM), set it to DC Volts. With the fuse removed but the battery reconnected (exercise caution!), touch the black probe to a known good ground (unpainted metal on engine/body). Touch the red probe to the contacts inside the fuse socket designated for Fuse #4. Turn the ignition key to the RUN position (don't crank). You should measure battery voltage (around 12V) only at one side of the fuse socket. This confirms power is getting to the fuse. The other side should show no voltage without the fuse. Do not bridge the socket contacts. Re-disconnect the battery after testing.
  8. Replace Blown Fuse: If the fuse is blown, replace it with a new fuse of the EXACT SAME AMPERAGE: 15 Amp (15A). NEVER substitute a higher amperage fuse or any metal object. Use a quality automotive fuse. Simply push the new fuse firmly into the socket until it seats completely.
  9. Reconnect & Test: Securely reconnect the negative battery terminal. Reattach the PDB lid. Try starting the vehicle. If it starts and runs, the blown fuse may have been the cause. However, fuses blow for a reason. A new fuse blowing immediately indicates a serious short circuit downstream (like in the fuel pump, wiring, or relay) that MUST be professionally diagnosed.

6. Why Would the Fuel Pump Fuse Blow?

Fuses protect wiring from excessive current caused by a short circuit or overload. Common reasons the fuel pump fuse (F4, 15A) blows in a 1999 Explorer include:

  • Failing Fuel Pump: The pump motor itself can develop internal shorts drawing excessive current. This is a common failure point as pumps age.
  • Damaged Wiring: Wires in the fuel pump circuit (running from the PDB, through the relay, inertia switch, to the fuel pump) can become chafed, pinched, or corroded, causing insulation breakdown and shorting to ground (vehicle chassis).
  • Faulty Fuel Pump Relay: An internal failure of the relay itself can cause excess current draw or send voltage where it shouldn't.
  • Inertia Switch Malfunction: (See Section 7) While less common for blowing the fuse directly, damage to this switch or its wiring could potentially lead to a short.
  • Collision or Severe Impact: Though the inertia switch should cut power first, a severe impact could cause multiple wiring issues.

7. Understanding the Fuel Pump Shutoff (Inertia) Switch

The 1999 Explorer has an inertia switch (or impact switch) in the fuel pump circuit. Its primary job is to cut power to the fuel pump in the event of a collision to reduce fire risk. It is NOT a fuse. It resets manually.

  • Location: Inside the cabin. It's tucked away behind the kick panel on the passenger side front footwell. You'll need to remove a plastic trim panel (knee bolster) held by several screws (usually Phillips or Torx) to access it. Look for a small red or black rectangular button near the top of the inner fender wall.
  • Function: A sudden impact triggers a mechanism inside the switch, disconnecting the circuit. If your fuse is good, the relay clicks, but the pump gets no power, check this switch.
  • Reset: Press the small button firmly on the top of the switch until it clicks into place. You might hear a faint click from the fuel system when turning the key to RUN if this was the issue.
  • Not the Fuse Cause: While a faulty inertia switch wiring can theoretically cause a short that blows the fuse, it's more common for a faulty switch to simply interrupt power (like an open circuit). If the switch tripped, the fuse shouldn't be blown; it simply breaks the connection.

8. Symptoms of a Blown Fuel Pump Fuse

  • Engine Cranks But Doesn't Start: The most common symptom. The engine cranks over normally with the starter but never catches or starts because no fuel is being delivered.
  • No Sound from Fuel Pump: When you turn the ignition key to the RUN position (without cranking the engine), you should hear a faint whirring/humming sound coming from the rear of the vehicle (location of the fuel tank) for about 2-3 seconds. The absence of this sound strongly suggests a lack of power to the pump, potentially due to the blown fuse. (Also check relay, inertia switch, pump itself).
  • Sudden Engine Shutdown: While driving, the engine may suddenly die without warning if the fuse blows due to an overload/short developing while driving.
  • Other Electrical Issues: If an overload caused the fuse to blow, you might notice flickering dash lights beforehand, though the fuse blowing usually happens very quickly.

9. Safety Precautions & Best Practices

  • Disconnect Battery: ALWAYS disconnect the negative (-) battery terminal before working on any electrical components, especially those in the fuel system. This prevents sparks, potential short circuits, and shocks.
  • Use Correct Amperage Fuse: ONLY replace a blown fuse with one of the identical amperage rating (15A). Using a higher amperage fuse bypasses the protection and can cause wiring to overheat and melt, creating a fire hazard. Using a lower amperage fuse will cause it to blow unnecessarily.
  • Address the Cause: A blown fuse is a symptom. Repeatedly replacing a fuse without diagnosing why it blew risks significant damage, including fire. If the new fuse blows immediately, do NOT keep replacing it. Professional diagnosis is essential.
  • Check Wiring: Visually inspect as much of the fuel pump wiring harness as possible, especially near connectors, sharp edges, and the fuel tank area, for signs of damage.
  • Fire Extinguisher: Have one nearby when working on vehicle electrical systems as a precaution.
  • Proper Tools: Use the fuse puller tool or needle-nose pliers carefully. Avoid damaging the fuse socket contacts. A multimeter (DMM) is highly recommended for testing voltage and continuity.

Conclusion

Knowing the precise location of the fuel pump fuse (Fuse #4, 15A, in the Power Distribution Box under the hood) is essential for diagnosing fuel delivery problems in your 1999 Ford Explorer. Always start by disconnecting the battery, locating the PDB diagram, finding Fuse #4, and carefully inspecting it. Remember that this fuse protects vital wiring, and replacing it with the correct amperage is critical. However, a blown fuse is always a warning sign of an underlying problem that must be investigated to prevent recurrence and ensure safe vehicle operation. For persistent issues or immediately re-blowing fuses, consult a qualified automotive technician.

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