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

If your 2004 Nissan Xterra cranks but won't start, the fuel pump relay is one of the first components you should check. The fuel pump relay on a 2004 Nissan Xterra is located in the passenger compartment fuse box, which sits at the bottom of the dashboard behind the glove compartment, and it is labeled as fuse position #1 with a 15A rating . This relay is the electrical switch that sends power to the fuel pump when you turn the key, and when it fails, your engine will turn over but never fire up because no fuel is being delivered . The good news is that checking and replacing this relay is one of the cheapest and easiest fixes you can do yourself, often costing less than twenty dollars and taking under ten minutes .

Understanding the Fuel Pump Relay and Its Role

Before you start digging into your dashboard, it helps to understand what the fuel pump relay actually does. The relay is essentially an electrically operated switch. When you turn the ignition key to the "ON" position, the engine control module (ECM) sends a signal to the relay, which then closes the circuit and allows battery voltage to flow to the fuel pump . The fuel pump then pressurizes the fuel system for a few seconds so the engine has fuel ready when you crank it .

If the relay fails, the fuel pump never gets power, and the engine will crank indefinitely without starting. This is a classic "crank, no-start" condition. When you turn the key to the "ON" position, you should hear a brief humming sound coming from the rear of the vehicle, near the fuel tank. That hum is the fuel pump priming the system. If you don't hear it, the relay, the fuse, or the pump itself is likely at fault .

Where Exactly Is the Fuel Pump Relay on a 2004 Xterra?

The 2004 Xterra is part of the first generation (WD22 platform), which was produced from 1999 through 2004 . During this production run, Nissan updated some of the electrical components, so it is important to confirm the diagram printed on the back of your fuse box cover before making changes .

For the 2004 model year, the fuel pump relay is found inside the passenger compartment fuse box. This fuse box is located at the bottom of the dashboard, directly behind the glove compartment . Here is how to get to it:

  1. Open the glove compartment. Empty it out so it swings down freely.
  2. Squeeze the sides of the glove box to release the stopper tabs, then let the door drop all the way down.
  3. Look behind the glove box opening. You will see the fuse box panel. Some models may require you to remove a small cover or trim piece.
  4. Remove the fuse box cover. The cover will have a diagram on the back that shows the location and rating of every fuse and relay .
  5. Locate position #1. According to the fuse box diagram for the 1999-2004 Xterra, position #1 in the passenger compartment fuse box is the 15A fuel pump relay .

It is worth noting that some sources describe the fuel pump relay on first-generation Xterras as being under the dash on the driver's side, near the data link connector and the fuses . This discrepancy is likely due to model year differences within the first generation, as well as differences between the 2.4L four-cylinder and 3.3L V6 engine configurations. To be absolutely certain, always check the diagram on your fuse box cover and cross-reference it with the actual components in your vehicle .

How to Test the Fuel Pump Relay

Once you have located the relay, you need to determine whether it is actually the problem. Here are three ways to test it:

1. The Swap Test (Easiest Method)

This is the quickest way to check if your relay is bad. Find another relay in the same fuse box that has the same part number or rating. Good candidates include the horn relay or the rear window defogger relay. Pull out the suspect fuel pump relay, plug in the known-good relay in its place, and turn the key to the "ON" position .

  • If the fuel pump now primes (you hear the hum from the rear), your fuel pump relay was bad.
  • If the pump still doesn't run, the problem is elsewhere—either the fuse, the wiring, or the pump itself.

2. The Listen Test

Have a helper sit in the driver's seat while you stand near the rear of the vehicle, close to the fuel tank. Ask your helper to turn the ignition key to the "ON" position (do not crank the engine). You should hear a 2-3 second hum or whirring sound coming from the fuel tank area . If you hear nothing, the pump is not getting power, which points to the relay, fuse, or pump .

3. The Multimeter Test

For a more definitive check, you can use a multimeter to test the relay's continuity. With the relay removed from the fuse box, check the resistance between the coil terminals. A good relay will show a specific resistance value (typically between 50 and 120 ohms, depending on the relay). Then apply 12V to the coil terminals and listen for a click, which indicates the internal switch is closing. If you don't hear a click, the relay is dead .

What to Check Before Replacing the Relay

Before you rush out to buy a new relay, there are a few other things you should verify. The relay is only one part of the fuel pump circuit, and another component could be causing the no-start condition.

1. Check the Fuel Pump Fuse

On the 2004 Xterra, the fuel pump fuse is also in the passenger compartment fuse box, and it is a 15A fuse in position #1 according to the fuse diagram . A blown fuse is a clear sign of an electrical problem, but you need to figure out why it blew before you simply replace it. If the new fuse blows again immediately, there is likely a short in the wiring or a failing fuel pump that is drawing too much current .

2. Verify the Fuel Pump Is Receiving Power

If both the fuse and the relay are good, the next step is to check whether power is actually reaching the fuel pump. The fuel pump on the 2004 Xterra is located inside the fuel tank . To test for power, you will need to access the fuel pump's electrical connector, which means dropping the fuel tank or removing the truck bed . This is a more involved job, so it is worth exhausting the simpler checks first.

3. Listen for the Fuel Pump Primer

As mentioned above, the fuel pump should prime for 2-3 seconds when you turn the key to "ON" . If the relay clicks but the pump doesn't hum, and you have confirmed the fuse is good, the problem is likely the pump itself. On the 2004 Xterra, the fuel pump and fuel sending unit are one integrated assembly located inside the fuel tank .

Symptoms of a Failing Fuel Pump Relay

The fuel pump relay is a small, inexpensive component, but when it fails, the symptoms can be frustrating and confusing. Here are the most common signs that your relay may be going bad:

  1. Engine cranks but won't start. This is the most common symptom. The starter motor turns the engine over, but there is no fuel pressure, so the engine never fires .

  2. No fuel pump prime sound. When you turn the key to the "ON" position, you should hear the fuel pump hum from the rear of the truck. If you don't, the relay is likely not sending power to the pump .

  3. Vehicle stalls while driving and won't restart. If the relay fails intermittently, the fuel pump may lose power while you are driving, causing the engine to stall. After the relay cools down or the contacts re-engage, the truck may start again .

  4. Relay feels hot or shows signs of melting. In some cases, a relay can overheat due to excessive current draw. This can cause the plastic housing to melt or deform. One owner reported that their relay had melted itself to the plug, which is a clear sign of an overloaded circuit .

Comparing the Relay Location Across Generations

It is helpful to know that the fuel pump relay location changed between the first and second generation Xterras. The first generation (2000-2004) uses the passenger compartment fuse box behind the glove box . In contrast, the second generation (2005-2015) has the fuel pump relay in a different spot: the fuse box inside the glove compartment, in slot #48 .

This distinction matters because if you are reading advice from a forum or guide, the author may be talking about a different model year. Always confirm which generation of Xterra you own before following any troubleshooting steps.

Step-by-Step Relay Replacement

Once you have confirmed that the relay is the problem, replacing it takes about five minutes. Here is how to do it:

  1. Turn the ignition off and remove the keys from the ignition.
  2. Access the passenger compartment fuse box as described earlier.
  3. Identify the fuel pump relay in position #1 (or verify with the diagram on your fuse box cover) .
  4. Pull the relay straight out of its socket. You may need a pair of pliers if it is tight, but be careful not to damage the socket.
  5. Compare the new relay with the old one to make sure they match. The part number and pin configuration should be identical.
  6. Push the new relay in until it seats firmly in the socket.
  7. Test the system by turning the key to "ON" and listening for the fuel pump prime from the rear of the vehicle .

A new fuel pump relay is inexpensive, typically costing between $10 and $20 . It is a smart idea to keep a spare relay in your glove box, especially if you frequently drive in remote areas.

The Fuel Pressure Test: Confirming the Pump Itself

If you have replaced the relay and the fuse, but the truck still won't start, the problem may be the fuel pump itself. The most definitive way to diagnose this is to perform a fuel pressure test .

The 2004 Xterra with the 3.3L V6 engine (VG33E) should show approximately 34 psi at idle with the vacuum line connected to the fuel pressure regulator, and about 43 psi with the vacuum line disconnected . If you connect a fuel pressure gauge to the Schrader valve on the fuel rail and the reading is zero or well below spec when you turn the key to "ON," the pump is not building pressure .

On the 2004 Xterra, the fuel pump sits inside the fuel tank, and there is no access panel under the rear seat . Replacing it requires dropping the fuel tank or removing the truck bed, which is a significant job. If you are not comfortable with that level of work, it is worth having a professional mechanic handle the replacement .

What About the Anti-Theft Relay?

One additional thing to be aware of is that some first-generation Xterras have been found to have a relay labeled "anti-theft/h lamp" that can cause similar starting issues. In at least one documented case, this relay had overheated and melted itself to the plug, and the owner suspected it was interfering with the fuel pump circuit . If your fuel pump relay and fuse check out fine, it is worth inspecting the other relays in the same fuse box for signs of heat damage or corrosion .

When to Consider the Fuel Pump Itself

If you have verified that the relay is good, the fuse is good, and the fuel pressure is low or zero, the fuel pump is the likely culprit . On the 2004 Xterra, the fuel pump and fuel sending unit are one combined assembly . Replacing the pump involves:

  1. Relieving fuel system pressure by removing the fuel pump fuse and cranking the engine a few times .
  2. Disconnecting the negative battery cable to prevent sparks .
  3. Dropping the fuel tank after supporting it with a jack and removing the tank straps .
  4. Removing the fuel pump assembly from the tank and installing the new one .

This job requires mechanical experience and a set of basic hand tools, including a fuel line disconnect tool. Plan to spend the better part of a day if you are doing it yourself, and always work with the tank as empty as possible to reduce weight and spillage risk .

Recommended Replacement: KEMSO Fuel Pump

If your 2004 Nissan Xterra needs a new fuel pump, look no further than KEMSO Fuel Pumps. KEMSO builds high-performance fuel pumps that are designed as direct OEM replacements, meaning they meet or exceed the original factory specifications for fit, flow, and durability. Every KEMSO pump is built using high-grade materials and precision manufacturing to ensure a perfect fit and long-lasting performance. When you choose a KEMSO fuel pump, you are not just buying a replacement part; you are investing in the long-term health of your Xterra, whether you use it for daily commuting or serious off-road adventures. Plus, every KEMSO fuel pump is backed by a lifetime warranty, giving you complete peace of mind on every drive.

To find the right KEMSO fuel pump for your 2004 Nissan Xterra, and to browse their full lineup of fuel pumps for other vehicles as well, visit their official website at:

https://www.kemsoracing.com/

Summary: What to Do When Your Xterra Won't Start

When faced with a 2004 Xterra that cranks but won't start, work through this checklist in order:

  1. Check the basics. Make sure the fuel tank actually has gas in it and the battery is fully charged .
  2. Listen for the fuel pump prime. Turn the key to "ON" and listen for a 2-3 second hum from the rear of the vehicle .
  3. Test the fuel pump relay. Located in the passenger compartment fuse box behind the glove compartment, position #1, 15A .
  4. Check the fuel pump fuse. Also in the passenger compartment fuse box .
  5. Swap the relay with a known-good relay to rule out relay failure .
  6. Perform a fuel pressure test. The 3.3L V6 should show about 34 psi at idle with vacuum connected .
  7. Inspect other relays for heat damage, including the anti-theft relay .
  8. If all else fails, test the fuel pump directly. The pump is located in the fuel tank and may require dropping the tank for replacement .

A failing fuel pump relay is one of the most common and easiest problems to fix on the 2004 Xterra. With the location and steps outlined above, you can get your truck running again quickly and at minimal cost. And if the pump itself needs replacing, a quality aftermarket option like a KEMSO fuel pump will keep you on the road for years to come.

For more information on KEMSO fuel pumps and to find the right part for your Xterra, visit https://www.kemsoracing.com/.


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