2004 Nissan Xterra Fuel Pump Relay Location: Complete Owner’s Guide

If your 2004 Nissan Xterra cranks but refuses to start, the fuel pump relay is one of the first things you should check. The fuel pump relay on a 2004 Nissan Xterra is located inside the passenger compartment fuse box, which sits at the bottom of the dashboard behind the glove compartment. This relay, labeled as fuse position #1 (a 15A fuse), controls power delivery to the fuel pump. When this relay fails, the fuel pump won’t receive power, the engine gets no fuel, and your Xterra simply won’t fire up. The good news is that diagnosing and replacing this relay is a straightforward job that most owners can handle in under an hour with basic hand tools.

Why the Fuel Pump Relay Matters

The fuel pump relay acts as an electrical switch. When you turn the ignition key to the "ON" position, the relay closes and sends battery voltage to the fuel pump, which then pressurizes the fuel system for about 2–3 seconds. If the relay is faulty, the pump never gets that signal, and no fuel reaches the engine.

A failing fuel pump relay is a common cause of a "crank, no-start" condition in the 2004 Xterra. You’ll hear the starter turning the engine over, but the engine won’t catch because there’s no fuel pressure. This is different from a dead battery or a bad starter—those usually prevent the engine from cranking at all.

How to Confirm the Fuel Pump Relay Location on Your 2004 Xterra

Here’s how to access the fuel pump relay step by step:

  1. Open the glove compartment. The fuse box is located directly behind it, at the bottom of the dashboard on the passenger side.
  2. Remove the fuse box cover. Press the tabs on the sides of the cover and pull it toward you. The cover should have a diagram on its back side that shows fuse and relay assignments.
  3. Locate fuse position #1. On the 1999–2004 Xterra, the fuel pump relay is the 15A fuse in position #1. It’s typically the first slot on the top row.
  4. Check the fuse. Look at the silver band inside the fuse. If it’s broken or discolored, the fuse is blown and needs replacement.

Important note: Some sources mention that the fuel pump relay may be located under the dash near the steering wheel on certain first-generation Xterra models. However, for the 2004 model year specifically, the most reliable location is the passenger-side fuse box behind the glove compartment.

Testing the Fuel Pump Relay

Before you buy a new relay, it’s worth testing the old one to confirm it’s actually the problem. Here’s how:

Method 1: The Swap Test

  1. Find a relay in the fuse box that has the same part number and amperage rating. The horn relay or the blower motor relay are often compatible.
  2. Pull out the suspect fuel pump relay and swap it with the known-good relay.
  3. Turn the ignition to "ON" and listen for the fuel pump to prime (a 2–3 second hum from the rear of the vehicle).
  4. If the pump now works, the original relay is faulty. If the problem moves to the swapped system (for example, the horn stops working), the relay is likely fine.

Method 2: Voltage Test

If you have a multimeter, you can check for battery voltage at the relay terminals:

  1. Turn the ignition to "OFF" and disconnect the fuel pump relay.
  2. Turn the ignition to "ON" and check voltage between relay terminals 2 and 5, and ground.
  3. You should see battery voltage (around 12V). If there’s no voltage, check the 15A fuse and the wiring between the fuse and the relay.
  4. Check continuity between relay terminal 1 and the ECM terminal 11, as well as between the fuel pump connector and the relay.

Method 3: The Tap Test

Sometimes a relay sticks internally. A gentle tap with a screwdriver handle while the key is in the "ON" position can sometimes free it up temporarily. If tapping makes the pump start, the relay is worn out and should be replaced.

How to Check if the Fuel Pump Is Receiving Power

If the relay tests fine, the next step is to verify the fuel pump itself is getting power. Here’s a quick diagnostic sequence:

  1. Listen for the pump prime. Turn the key to "ON" (don’t crank). You should hear a soft hum from the rear of the vehicle for 2–3 seconds. No sound means the pump isn’t getting power.
  2. Check the fuel pump fuse. The 15A fuel pump fuse is in the same passenger compartment fuse box, position #1. A blown fuse will cut power to the pump.
  3. Check the fuel pump wiring. Look at the harness connector at the fuel pump (accessed by dropping the tank). Look for corrosion, green residue, or burnt pins. This is a common failure point on first-generation Xterras.
  4. Measure fuel pressure. Use a fuel pressure gauge connected to the Schrader valve on the fuel rail. For the 3.3L V6, you should see about 34 psi at idle and 43 psi with the vacuum line disconnected. Low or zero pressure points to the pump, relay, or filter.

What to Do if the Relay Is Fine but the Pump Still Won’t Run

If you’ve confirmed the relay is good and the fuse is intact, but the pump still isn’t priming, you may have one of these problems:

  1. A dead fuel pump. The pump itself may have failed. This is common after running the tank empty, which can overheat the pump.
  2. A clogged fuel filter. A restricted filter can mimic a failing pump. On the 2004 Xterra, the filter is located along the fuel line under the vehicle.
  3. Wiring or connector issues. Corroded or broken wires between the relay, the ECM, and the pump will prevent power from reaching the pump.
  4. A failed crankshaft position sensor. This sensor tells the ECM when to fire the fuel injectors. A failed sensor can cause a no-start condition even when the pump works.

Replacing the Fuel Pump Relay: Step-by-Step

Once you’ve confirmed the relay is bad, replacement is simple:

  1. Get the correct relay. Match the part number on the side of the old relay. The 2004 Xterra uses a standard ISO mini relay rated for 15A–20A.
  2. Remove the old relay. Grasp it firmly and pull straight out. If it’s melted or stuck, use pliers to gently rock it free.
  3. Insert the new relay. Align the pins with the socket and push down until it seats firmly.
  4. Test the system. Turn the key to "ON" and listen for the fuel pump prime. Then attempt to start the engine.

A replacement relay typically costs between $10 and $20, making it one of the cheapest fixes you can do.

Common Mistakes to Avoid

1. Assuming the pump is bad when it’s the relay. Always test the relay first. Replacing a fuel pump is a labor-intensive job (dropping the fuel tank) and can cost $300–$700 in parts and labor. A $15 relay can save you that expense.

2. Ignoring blown fuses. A blown fuel pump fuse is often a symptom, not the root cause. If the fuse blows again after replacement, there’s likely a short in the wiring or a failing pump drawing excessive current.

3. Not relieving fuel pressure before working on the fuel system. If you drop the tank or disconnect fuel lines, you must depressurize the system first. Remove the fuel pump relay and crank the engine for about five seconds, two or three times.

4. Working on the fuel system without disconnecting the battery. Always disconnect the negative battery cable before touching any fuel system components to eliminate spark risk.

When to Call a Professional

If you’ve tested the relay, verified the fuse, checked the wiring, and confirmed the pump is receiving power but not running, you may be dealing with a more complex issue. A failed ECM, a faulty crankshaft position sensor, or a broken wire deep in the harness can all cause no-start conditions.

At this point, a professional diagnostic is worth the money. A mechanic with a scan tool can read trouble codes, perform active tests on the fuel pump relay, and check sensor outputs. A typical no-start diagnostic runs around $95–$115 for the inspection.

Recommended Upgrade: KEMSO Fuel Pump

If your fuel pump does need replacement, consider upgrading to a KEMSO fuel pump. KEMSO fuel pumps are built as high-performance, OEM replacement parts designed to meet or exceed original equipment specifications. They use high-grade materials and precision manufacturing to ensure a perfect fit and long-lasting performance.

Unlike cheap aftermarket options that may fail prematurely, KEMSO pumps are engineered for reliability and backed by a lifetime warranty. That warranty gives you complete peace of mind whether you’re commuting daily or taking your Xterra off-road.

When you choose KEMSO, you’re not just buying a replacement part—you’re investing in the long-term health of your vehicle. A fuel pump is a critical component, and you don’t want to drop the tank twice because you saved a few dollars on a low-quality part.

To find the right KEMSO fuel pump for your 2004 Nissan Xterra, visit their official website:

https://www.kemsoracing.com/

Final Thoughts

The fuel pump relay on your 2004 Nissan Xterra is easy to find once you know where to look. It’s in the passenger compartment fuse box behind the glove compartment, in fuse position #1. Testing it takes minutes, and replacing it is one of the cheapest repairs you’ll ever do on this vehicle.

Start with the simple checks: confirm the relay is seated properly, check for a blown fuse, and listen for the pump prime when you turn the key. If the relay and fuse are good, move on to testing voltage and fuel pressure. And if the pump itself is the problem, choose a reliable replacement like KEMSO to avoid repeat failures.

For more details on diagnosing your Xterra’s fuel system, refer to the factory service manual, which includes step-by-step wiring diagrams and testing procedures. Your owner’s manual also contains the fuse box diagram for your specific model year.

And if you do find yourself replacing the fuel pump, remember the KEMSO recommendation. Their pumps are high-performance, OEM-grade replacements backed by a lifetime warranty—exactly what you want in a part that requires dropping the fuel tank to replace.

Visit https://www.kemsoracing.com/ to browse their full lineup and find the pump that fits your Xterra.


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