1999 Ford Expedition Fuel Pump Fuse Location: Complete Troubleshooting Guide

The fuel pump fuse for your 1999 Ford Expedition is located in the main Power Distribution Center (PDC) under the hood. Specifically, it is designated as fuse #22 (20 Amp) within this box. This fuse provides critical power directly to the fuel pump circuit. If your Expedition cranks but won't start, checking and replacing this specific fuse is always the absolute first step due to its fundamental role in delivering electricity to the fuel pump motor. Ignoring this simple check wastes time troubleshooting more complex components prematurely.

1. Locating the Primary Power Distribution Center (PDC)
The Power Distribution Center (PDC) is the main under-hood fuse and relay box in your 1999 Ford Expedition. Forget the fuse panel inside the vehicle's cabin – that is the secondary Central Junction Box (CJB) and does not contain the fuel pump fuse. To find the PDC:

  • Open the Expedition's hood.
  • Locate the vehicle's battery. It's on the passenger side of the engine compartment.
  • Directly in front of the battery, secured to the inner fender well close to the brake fluid reservoir, you will see a relatively large, rectangular black plastic box with a lid secured by multiple tabs or clips.
  • Carefully release the securing tabs or clips around the perimeter of the PDC lid (these clips can become brittle with age; use steady pressure). Lift the lid straight up to remove it. You will now see an array of fuses and relays, often with an identification diagram printed inside the lid or on a label affixed to the bottom of the box.

2. Identifying and Accessing Fuse #22 (20 Amp)

  • Look for the Fuse Legend: Locate the fuse identification chart inside the PDC lid or printed directly on the PDC housing. If faded or missing, you can find official diagrams in your Owner's Manual (check the index under "Fuses") or readily available online from reputable Ford parts sites or service manual providers. Never guess the fuse location based on slot shape.
  • Find Fuse Position #22: Scan the diagram specifically for fuse #22. Its location is fixed relative to the other fuses and relays, even if the diagram is worn. In the standard layout for the 1999 Expedition, fuse #22 is situated on the forward-facing side of the PDC (the side closest to the front grille), typically grouped with several other fuses of similar amperage (like 20A mini-fuses).
  • Visual Confirmation: Once you've identified slot #22 on the diagram, locate the actual slot within the PDC. You will see a small plastic cavity containing a fuse. The fuel pump fuse in your 1999 Expedition is a Standard Blade Fuse, specifically the "Mini" size (approximately 10.9mm x 3.6mm x 15.9mm). It should be rated for 20 Amps. The plastic housing of the fuse itself is typically blue. However, never rely solely on color – a blown fuse might still show its original color! Confirming the slot number (#22) is paramount.

3. Essential Safety Precautions Before Handling Fuses
Always prioritize safety when working in the engine bay electrical system:

  • Turn the Ignition OFF: Ensure the key is removed from the ignition switch. Set the parking brake firmly.
  • Disconnect the Battery Ground Cable (Highly Recommended): This is the single best way to prevent accidental shorts, sparks, or electrical surges while handling fuses. Loosen the nut securing the NEGATIVE (-) battery terminal clamp to the battery post using the correct size wrench (usually 10mm or 8mm). Lift the cable end completely off the battery post and secure it away from the terminal. Insulate it if possible. Important: Only disconnect the negative terminal.
  • Use Dedicated Tools: Use a fuse puller tool (often included in the PDC lid or glovebox fuse kit) or needle-nose pliers with insulated handles to grip the fuse. Pull straight out gently. Do not use excessive force which could damage the fuse slot contacts.
  • Inspect Fuse Carefully: Hold the extracted fuse (#22) up to a strong light. Look through the semi-transparent plastic body at the thin metal conductor strip inside. A good fuse will show a continuous, unbroken metal link connecting the two plastic blades. A blown fuse will have a visibly melted or broken gap in this metal strip. This gap interrupts the electrical circuit, halting power flow to the fuel pump. Even a slightly broken strand indicates failure – if in doubt, replace it.

4. Replacing a Blown Fuel Pump Fuse
If you have confirmed fuse #22 is blown:

  • Purchase Correct Replacement: Obtain a new 20 Amp Mini Blade Fuse. Auto parts stores carry them readily. Using a higher amperage fuse (e.g., 25A or 30A) is extremely dangerous as it can lead to overheating wires and potentially an under-hood fire. Using a lower amperage fuse will cause it to blow immediately. Use only a 20 Amp fuse.
  • Insert New Fuse: With the ignition OFF and battery negative cable still disconnected for maximum safety, align the new 20A fuse blades with the slot contacts in position #22. Push the fuse firmly and squarely into place until it seats completely. It should sit at the same depth as surrounding fuses with no part sticking up abnormally.
  • Reconnect Battery: Securely reconnect the negative battery cable to its terminal post and tighten the clamp nut firmly. Ensure no tools or loose objects are left near battery terminals.

5. Critical Step After Replacement: Root Cause Check
Replacing a blown fuse might restore operation temporarily. However, fuses blow for a reason – they protect the wiring harness from overload damage. A blown fuel pump fuse almost certainly indicates an underlying problem that caused excessive current draw. Ignoring this risks immediate re-blowing of the new fuse or worse.

  • Does it Blow Again? Turn the ignition key to the RUN position (do not start the engine yet). The fuel pump should run for 1-2 seconds to prime the system. Listen carefully near the rear of the vehicle. If you hear the pump whirring normally, try starting the engine. If it starts and runs, monitor closely. If the new fuse blows again at any point (during priming or operation), STOP DRIVING. The underlying electrical fault requires immediate professional diagnosis to prevent potential fire or further electrical damage.
  • Common Causes of Fuel Pump Fuse Failure: The most likely culprits include:
    • Fuel Pump Motor Failure: A failing or seized pump motor draws excessive current, overwhelming the fuse.
    • Chafed or Damaged Wiring: The wiring harness running from the PDC, through the vehicle body, down the frame rail, to the fuel tank pump assembly can get damaged by road debris, corrosion, or rubbing against sharp edges.
    • Faulty Fuel Pump Relay: While a bad relay usually causes a no-power situation (open circuit) rather than a short circuit drawing too much current, severe internal relay shorts can potentially blow the fuse.
    • Short Circuits Elsewhere: Though less common specific to this fuse, other faults causing dead shorts on circuits protected by fuse #22 will cause it to blow.

6. When the Fuse is Good, But the Pump Still Doesn't Run (Beyond Fuse #22)
If fuse #22 is visually intact and tests good with a multimeter (see next section), but the fuel pump doesn't activate:

  • Check the Fuel Pump Relay (Crucial Component): The fuel pump relay for the 1999 Expedition is also located in the under-hood Power Distribution Center (PDC). Refer to the PDC diagram to locate Relay #202 (this is the standard designation for fuel pump relay on most Ford trucks of this era). It is physically located near fuse #22.
  • Identifying Relay #202: The relay is a black or dark gray cube-like component, about 1" square, with four or five metal prongs plugging into a socket. It will likely be marked "FP", "F/PMP", "F/P", or the number "202" on its top or plastic base.
  • Testing/Replacing the Relay: Relays are cheap and very common failure points.
    • Swap Test: Find another relay in the PDC with the exact same part number printed on it (common ones include the horn relay, blower motor relay (Hi), or A/C clutch relay). Swap the fuel pump relay (#202) with the known good relay. If the pump starts working, the original relay is faulty and needs replacement. If not, proceed with power tests.
    • Professional Diagnosis: Testing a relay properly requires checking for power input, control signal activation (from the PCM), and output switching using a multimeter. If uncomfortable performing these steps, replacement is a low-cost diagnostic attempt. Purchase a correct replacement relay (Motorcraft parts are recommended for compatibility).
  • Check the Inertia Fuel Shutoff (Safety Switch): The 1999 Expedition has an inertia switch designed to automatically cut power to the fuel pump in the event of a collision. It can sometimes trip during heavy bumps or minor impacts. It's located in the passenger footwell, typically mounted low on the toe-kick panel or the inner sidewall beneath the glovebox area. Look for a small rectangular plastic device (about 1" x 2") often with a red rubber reset button on top or a small push-button cover. Press the reset button firmly. You should hear or feel a distinct click when it resets. Attempt to start the vehicle.
  • Check For Power at Fuse #22 (Multimeter Required): Verify circuit function.
    • Set digital multimeter to measure DC Volts (20V range).
    • Reconnect battery negative cable. With the PDC lid off, carefully probe the exposed metal contacts on top of fuse #22 (one probe on each end) or probe the small metal test points often molded beside each fuse slot in the plastic. Do not force probes into fuse slots; use top contacts/test points.
    • Turn ignition key to RUN position (engine off). You should measure battery voltage (approx. 12V) across fuse #22. If you get 0V, it indicates a problem upstream of the fuse (blown main fuse, ignition switch issue, or open circuit wiring between battery and PDC) which requires further diagnosis.
  • Final Considerations: If fuse #22 has power, the relay is functional, the inertia switch is reset, but the pump still gets no power, the issue lies downstream. This could be:
    • Open Circuit Wiring: Broken wire between the PDC and the fuel pump, bad connections, corrosion at connectors (especially the tank harness connector).
    • Fuel Pump Connector Issue: Corrosion or damage at the electrical connector on the top of the fuel tank pump module.
    • Failed Fuel Pump Motor: The pump motor windings can fail completely.
    • PCM (Powertrain Control Module) Control Failure: Though rare as a sole cause for no power (it usually disables the pump by grounding the relay control circuit), a severe PCM issue could prevent activation.

7. Necessary Tools and Materials for the Job

  • Correct Replacement Fuses: 20 Amp Mini Blade Fuses (Buy a package of 5 or 10).
  • Fuse Puller Tool: (Usually included in PDC lid or vehicle tool kit; needle-nose pliers with insulated handles work if careful).
  • Flashlight: Essential for visibility under dash and in engine bay.
  • Multimeter (Digital Voltmeter/Ohmmeter): Crucial for accurate diagnosis beyond visual inspection. Basic models are affordable and invaluable.
  • Basic Hand Tools: Wrenches/Sockets for disconnecting battery terminal (usually 10mm or 8mm).
  • Protective Gloves & Eye Protection: Safety first.

8. When Professional Help is Mandatory
Diagnosing fuel system and electrical faults requires specific tools and expertise. Seek professional assistance from a qualified automotive technician in these situations:

  • The fuel pump fuse (#22) blows repeatedly after replacement.
  • You have confirmed power to the fuse but the fuel pump still gets no power (and you've checked the relay and inertia switch).
  • You hear the fuel pump running briefly but the engine fails to start or starts then stalls.
  • You suspect wiring harness damage underneath the vehicle or near the fuel tank.
  • You lack the tools (especially a multimeter) or confidence to perform voltage and relay circuit tests safely.
  • There are signs of melting wiring, burning smells, or other severe electrical issues near the fuse box or fuel tank.

Understanding the precise location of the 1999 Ford Expedition fuel pump fuse (#22 in the under-hood PDC) empowers you to tackle the first and most critical step in diagnosing a sudden no-start condition. Performing a visual fuse check and replacement is a simple process achievable by most vehicle owners. However, remembering that fuse failures are symptom, not the root cause, is paramount. Persistent electrical problems demand thorough inspection and testing to identify and repair the underlying fault, ensuring the safety and reliability of your vehicle's fuel system. Always prioritize safety procedures, use correct replacement parts (specifically 20A mini fuse), and seek professional assistance whenever the diagnosis extends beyond a basic fuse replacement or the symptoms suggest a more complex failure. Knowing where and how to check this crucial fuse can prevent costly unnecessary towing and streamline the repair process.

Back to blog