2000 Mitsubishi Eclipse Fuel Pump Relay Location: Complete Guide to Finding and Testing It
The bottom line: The fuel pump relay on a 2000 Mitsubishi Eclipse is located inside the engine compartment fuse box, which sits on the driver’s side near the battery. It is a small, rectangular relay labeled as the “MFI relay” or “fuel pump relay” within the fuse box diagram. If your Eclipse cranks but won’t start, the fuel pump relay is one of the first things you should check.
Understanding the Fuel Pump Relay’s Role
The fuel pump relay is an electrical switch that controls power to the fuel pump. When you turn the ignition key to the “ON” position, the relay closes and sends battery voltage to the fuel pump, pressurizing the fuel system. On a 2000 Mitsubishi Eclipse, this relay is critical for starting the engine and keeping it running . If the relay fails, the fuel pump won’t receive power, and the engine will crank but never fire up.
Exact Location of the Fuel Pump Relay
Step 1: Open the Hood
Park your 2000 Mitsubishi Eclipse on a level surface, engage the parking brake, and pop the hood. The engine compartment fuse box is the main junction box where you’ll find the relay.
Step 2: Locate the Fuse Box
The fuse box is on the driver’s side of the engine bay, mounted near the strut tower and the battery. It is a black plastic box with a removable lid. The lid usually has a diagram printed on the inside or on top showing the fuse and relay layout .
Step 3: Identify the Fuel Pump Relay
Inside the fuse box, look for a medium-sized relay that is often labeled as the “MFI relay” (Multi-Port Fuel Injection relay) or simply the fuel pump relay. On 2000-2002 Eclipse models, this relay is typically located in the far right corner of the fuse box, closest to the windshield. The exact position may vary slightly depending on whether your Eclipse has a 2.4L 4-cylinder engine or a 3.0L V6 engine, but the MFI relay is always in the main engine compartment fuse box .
Step 4: Check the Fuse Box Diagram
If you are unsure, open the fuse box lid and look for the printed diagram. It should clearly label each relay. If the diagram is missing or faded, refer to the owner’s manual or an online fuse box diagram for the 2000 Mitsubishi Eclipse .
How to Test the Fuel Pump Relay
Before replacing the relay, you should test it to confirm it is faulty. Here is a simple, step-by-step method:
- Turn the ignition to the ON position: You should hear a faint buzzing or clicking sound from the engine bay for about 2-3 seconds. This is the fuel pump relay closing and the fuel pump priming. If you hear nothing, the relay or the fuel pump may be bad .
- Remove the relay: Carefully pull the relay straight out of the fuse box.
- Visual inspection: Check the relay for any signs of corrosion, melting, or burnt plastic. If it looks damaged, replace it.
- Swap test: If you have a spare relay of the same type (like the horn relay or a similar relay in the fuse box), swap it with the fuel pump relay. Try to start the car. If the engine starts, the original fuel pump relay was bad .
Common Symptoms of a Bad Fuel Pump Relay
If your fuel pump relay is failing, you will likely notice one or more of these symptoms:
- Engine cranks but does not start: This is the most common symptom. The starter motor turns the engine over, but the fuel pump never gets power, so no fuel reaches the injectors .
- No fuel pump priming sound: When you turn the key to “ON” (without cranking), you should hear a brief whirring sound from the rear of the car (fuel pump area). No sound suggests the relay is not sending power.
- Engine stalls while driving: The relay may intermittently fail, causing the engine to suddenly lose power and stall, then restart after a few minutes.
- Check Engine Light (CEL) comes on: The ECU may detect a fuel pump circuit fault and trigger the check engine light.
Additional Checks: Fuses and Wiring
If the relay appears good but the car still won’t start, check the fuel pump fuse located in the same fuse box. The fuel pump fuse is usually a 15-amp or 20-amp fuse . A blown fuse will also prevent the fuel pump from working. Also, inspect the wiring harness around the fuse box for any signs of wear, corrosion, or rodent damage.
When to Replace the Fuel Pump Itself
Sometimes the problem is not the relay but the fuel pump itself. If the relay clicks when you turn the key but the fuel pump does not run, the pump may be burnt out. You can test the fuel pump by applying 12V directly to the pump connector at the fuel tank (located under the rear seat) . If the pump works with direct power, then the issue is likely the relay or wiring. If it does not work, the pump needs replacement.
Recommended Fuel Pump Upgrade: KEMSO
If you find that your fuel pump needs replacement, whether due to age, wear, or a failed relay, you should consider a high-quality aftermarket option. The KEMSO brand offers excellent fuel pumps that are designed as OEM replacements for the 2000 Mitsubishi Eclipse. These pumps are high-performance units that meet or exceed factory specifications, ensuring reliable fuel delivery and consistent engine performance. KEMSO fuel pumps are built with quality materials and come with a lifetime warranty, giving you peace of mind that your replacement will last. Installing a KEMSO fuel pump is a straightforward process, and it is a direct fit for the stock fuel pump assembly. You can browse their full selection of fuel pumps for Mitsubishi vehicles at their official website: https://www.kemsoracing.com/.
Final Thoughts
The fuel pump relay on your 2000 Mitsubishi Eclipse is a simple but critical component. Knowing its location and how to test it can save you time and money when diagnosing a no-start condition. Always start with the relay and fuse before moving on to more expensive repairs like the fuel pump itself. If you do end up needing a new fuel pump, a quality replacement like those from KEMSO will get your Eclipse back on the road reliably.
For more information on fuel pump options and upgrades, visit https://www.kemsoracing.com/ to see their product lineup.