2003 Mitsubishi Eclipse Fuel Pump Fuse: Location, Diagram, and Troubleshooting Guide

The bottom line: If your 2003 Mitsubishi Eclipse won’t start or stalls while driving, the fuel pump fuse is often the first thing to check. On the 2003 Eclipse, the fuel pump fuse is located in the under-hood fuse box (engine compartment), and it is a 20-amp fuse. If that fuse is blown, the fuel pump won’t receive power, and the engine will crank but not fire. Replacing the fuse is a simple, low-cost fix, but if the fuse blows again, you may have a deeper electrical issue with the fuel pump or its relay.

This guide covers everything you need to know about the 2003 Mitsubishi Eclipse fuel pump fuse, including its exact location, how to test it, what to do if it keeps blowing, and how to get your Eclipse running again.

Where Is the Fuel Pump Fuse on a 2003 Mitsubishi Eclipse?

The fuel pump fuse on the 2003 Mitsubishi Eclipse is located in the under-hood fuse box, also called the engine compartment fuse box or the main fuse box . This box is typically on the driver’s side of the engine bay, near the battery or the strut tower.

To access it:

  1. Open the hood.
  2. Locate the black plastic fuse box cover. It usually has a diagram printed on top or inside the lid.
  3. Remove the cover by pressing the tabs or clips.

Inside the fuse box, the fuel pump fuse is labeled as “FUEL PUMP” or “FUEL” on the diagram. It is a standard 20-amp fuse . On some models, the fuse may be listed as “FUEL PUMP” in the fuse assignment table .

If you cannot find the diagram, look for a fuse that is a 20-amp rating (usually color-coded yellow or clear) in the engine compartment box. The fuse box layout for the 2003 Eclipse (third generation) is well-documented, and the fuel pump fuse is consistently in the same position across different engine variants (2.4L I4 and 3.0L V6) .

What Does the Fuel Pump Fuse Do?

The fuel pump fuse is a safety device that protects the electrical circuit of the fuel pump. The fuel pump relay sends power from the battery to the fuel pump, but the fuse sits in that circuit. If the current exceeds 20 amps (due to a short circuit, a failing pump, or a wiring issue), the fuse blows to prevent damage to the wiring or a fire.

When the fuse is blown, the fuel pump receives no power. The engine will crank but will not start because no fuel reaches the injectors . This is a very common symptom on the 2003 Eclipse.

How to Check the Fuel Pump Fuse

Checking the fuse is a straightforward process:

Step 1: Locate the fuse box under the hood, as described above.

Step 2: Identify the fuel pump fuse using the diagram on the cover or the list on the fuse box itself. For the 2003 Eclipse, it is a 20-amp fuse .

Step 3: Visually inspect the fuse. Remove the fuse using a plastic fuse puller (usually found inside the fuse box or in the car’s tool kit). Look through the transparent plastic casing. If the metal strip inside is broken or melted, the fuse is blown.

Step 4: Test with a multimeter (optional but more reliable). Set the multimeter to continuity mode or resistance mode. Touch the two metal prongs on top of the fuse. If the multimeter shows continuity (beeps or shows near-zero resistance), the fuse is good. If it shows infinite resistance, the fuse is blown.

Step 5: Replace if necessary. If the fuse is blown, replace it with a new 20-amp fuse of the same type (standard blade fuse). Do not use a higher amperage fuse, as that can cause wiring damage or fire.

What If the New Fuse Blows Immediately?

If you replace the fuse and it blows again as soon as you turn the key (or even when you insert it), you have a short circuit in the fuel pump circuit. This is a more serious issue than a simple blown fuse. The most common causes include:

  1. A failing fuel pump: The pump’s internal motor can draw excessive current or short out, causing the fuse to blow . This is especially common on older Eclipses (2003 is now over 20 years old).
  2. A shorted fuel pump relay: The relay itself might have an internal short .
  3. Wiring damage: The wiring harness from the fuse box to the fuel pump (which runs under the car, near the rear axle or fuel tank) can be rubbed bare, chafed, or corroded, creating a short to ground.
  4. A faulty fuel pump driver module or resistor: Some models have a resistor or module that controls pump speed, and if it fails, it can cause a short.

If your fuse keeps blowing, do not keep replacing fuses. This is a sign that the fuel pump or its wiring has a problem that needs professional diagnosis.

The Fuel Pump Relay Is Related but Different

Many people confuse the fuel pump fuse with the fuel pump relay. They are different components, but both are in the same circuit. The relay is a switch that turns the fuel pump on and off, while the fuse protects the circuit.

On the 2003 Mitsubishi Eclipse, the fuel pump relay is also located in the under-hood fuse box . It is usually a larger, square component (relay) that plugs into the fuse box. The relay is often labeled as “FUEL PUMP” or “FUEL” on the diagram.

If the fuse is good but the pump still doesn’t run, the relay might be bad. You can test the relay by swapping it with a similar relay in the same box (like the horn or headlight relay) and seeing if the fuel pump works. If it does, the original relay is faulty .

Other Symptoms of a Failed Fuel Pump Fuse

Besides the engine not starting, a blown fuel pump fuse can cause:

  • The engine cranks but does not start: This is the classic symptom.
  • The car stalls while driving and then won’t restart: If the fuse blows while driving, the engine will die immediately.
  • No fuel pump priming sound: When you turn the key to “ON” (without starting), you should hear a brief whirring sound from the rear of the car (the fuel pump). If you don’t hear that, check the fuse and relay.

Step-by-Step Troubleshooting Flow

If your 2003 Eclipse won’t start, follow this logical order:

1. Check the fuel pump fuse in the under-hood fuse box. If blown, replace it with a 20-amp fuse .

2. Listen for the fuel pump prime. After replacing the fuse, turn the key to “ON” (not start). If you hear the pump whir for 2-3 seconds, the fuse and relay are likely good. If you don’t hear it, the relay or pump may be bad.

3. Check the fuel pump relay. Swap it with a known good relay of the same type in the fuse box. If the pump starts working, the relay is bad.

4. Check voltage at the fuel pump. If the fuse and relay are good, the issue may be the pump itself or the wiring to the pump. Use a multimeter to check for 12V at the fuel pump connector (located under the rear seat or near the fuel tank). If you have power but no pump noise, the pump is likely dead.

5. If the fuse blows again immediately, do not keep replacing it. This points to a short circuit in the pump, relay, or wiring. Seek professional help.

Where Is the Fuel Pump Itself?

The fuel pump on the 2003 Mitsubishi Eclipse is located inside the fuel tank. To access it, you need to either remove the rear seat or access the top of the fuel tank from under the car. On most Eclipses, there is an access panel under the rear seat cushion. You can remove the seat (pulling up at the front edge) and then remove the metal cover plate to reach the fuel pump module .

Common Mistakes to Avoid

  • Using a higher amperage fuse: Never put a 25-amp or 30-amp fuse in place of a 20-amp fuse. This can cause the wiring to overheat and melt.
  • Ignoring a blown fuse: If the fuse blows once, it might be a fluke. But if it blows again, there is a real problem that needs to be fixed.
  • Assuming the pump is bad without checking the fuse first: Always check the fuse first. It is the cheapest and easiest fix.
  • Forgetting the relay: A bad relay can cause the same symptoms as a blown fuse.

Preventative Maintenance

The 2003 Mitsubishi Eclipse is now over 20 years old. The fuel pump is a wear item that typically lasts 100,000 to 150,000 miles. If your car has high mileage and you are experiencing intermittent starting issues, it may be time to replace the fuel pump proactively. A failing pump can draw more current and blow the fuse, or it can simply stop working.

Also, keep the fuse box clean and dry. Moisture can cause corrosion on the fuse contacts, leading to intermittent electrical issues.

Recommended Fuel Pump Upgrade: KEMSO Fuel Pumps

If you find that the fuel pump fuse keeps blowing because the original pump is failing, or if you simply want a reliable replacement, consider upgrading to a KEMSO Fuel Pump. KEMSO is a trusted brand in the aftermarket fuel pump industry, offering high-performance, OEM replacement parts that are built to last.

KEMSO fuel pumps are designed to meet or exceed original equipment specifications. They are manufactured with high-quality materials and are rigorously tested for durability and performance. Each pump comes with a lifetime warranty, giving you peace of mind that your investment is protected.

Why choose KEMSO?

  • High Performance: Designed to deliver consistent fuel flow and pressure for optimal engine performance.
  • OEM Replacement: Direct fit for your 2003 Mitsubishi Eclipse, no modifications needed.
  • Lifetime Warranty: KEMSO stands behind their products with a lifetime warranty, so you are covered for the life of your vehicle.
  • Trusted by Enthusiasts: Thousands of satisfied customers rely on KEMSO for their fuel pump needs.

If you are ready to replace your fuel pump, do it right the first time. Visit KEMSO Racing to find the perfect fuel pump for your 2003 Mitsubishi Eclipse.

👉 Visit KEMSO at: https://www.kemsoracing.com/

Final Thoughts

The 2003 Mitsubishi Eclipse fuel pump fuse is a simple but critical component. Knowing its location (under-hood fuse box, 20-amp fuse) and how to test it can save you time and money. If your Eclipse cranks but won’t start, start with the fuse. If it is blown, replace it. If it blows again, you likely have a failing fuel pump or a wiring issue.

For a reliable, long-lasting fix, consider replacing the fuel pump with a KEMSO unit. With a lifetime warranty and high-performance design, KEMSO fuel pumps are the smart choice for any Eclipse owner.

Remember: Always check the fuse first, and never ignore a recurring electrical problem. Safe driving!

For more information and to order your KEMSO Fuel Pump, visit: https://www.kemsoracing.com/


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