2007 Mitsubishi Eclipse Fuel Pump Relay Location: Quick Find, Symptoms, and Replacement

The bottom line up front: On the 2007 Mitsubishi Eclipse, the fuel pump relay is located on the far left side of the dashboard, behind the side panel that sits between the open driver's door and the dashboard itself. It sits in position one, which is the lower portion of that interior fuse panel. If your Eclipse cranks but won't start, stalls without warning, or you don't hear the fuel pump hum when you turn the key, this relay is the first thing to check.

What the Fuel Pump Relay Does

The fuel pump relay is an electronic switch. It sits between the car's computer and the fuel pump. When you turn the ignition key, the Powertrain Control Module sends a small electrical signal to the relay. That signal closes a set of internal contacts, which then allows full battery voltage to flow to the fuel pump. The pump primes the fuel system for a couple of seconds, then runs continuously while the engine is running.

When the relay fails, the pump loses power. No power means no fuel pressure. No fuel pressure means the engine either won't start or dies while you are driving.

How to Find the Relay on Your 2007 Eclipse

The 2007 Mitsubishi Eclipse fuel pump relay location is not in the engine bay. It is inside the cabin, on the driver's side.

Step-by-step location guide:

  1. Open the driver's door all the way.
  2. Look at the far left edge of the dashboard, right where it meets the door frame.
  3. You will see a removable plastic panel. It is the side cover of the dash.
  4. Gently pry that panel off. A trim tool or a flathead screwdriver wrapped in tape works best.
  5. Behind that panel is the interior fuse box.
  6. Find position one on that fuse panel. It is on the lower side. That is the fuel pump relay.

Important note: If you replace the relay and the car still won't start, the next suspect is the MFI relay, which also controls power to the fuel pump on this model.

Symptoms That Point to a Bad Fuel Pump Relay

A failing fuel pump relay rarely gives you a clear warning. It often acts like a flaky switch, cutting power at the worst possible moment. Here are the most common signs to watch for:

1. The Engine Cranks But Won't Start

This is the classic symptom. When you turn the key, the starter motor spins the engine over, but it never fires up. The engine has compression and spark, but it has no fuel. The relay has failed in the open position, so the pump never gets power.

2. The Engine Stalls Suddenly

If the relay drops out while you are driving, the fuel pump loses power instantly. The engine does not sputter or cough. It just shuts off. Some cars will restart after a few minutes once the relay cools down. Others will not start again until the relay is replaced.

3. No Noise From the Fuel Pump

Turn the key to the "ON" position but do not crank the engine. Listen carefully. You should hear a faint whirring or humming sound from the rear of the car, near the fuel tank. That sound is the pump priming the system. If you hear nothing, the pump is not getting power. The relay is your first suspect.

4. Intermittent Starting Issues

Some relays fail only when they get hot. The car starts fine in the morning, but after driving for twenty minutes, it stalls or refuses to restart. This thermal sensitivity is a common hallmark of a failing relay. The engine bay heat causes the internal coil or contacts to lose connection.

5. Check Engine Light

A bad relay can trigger the check engine light. When the pump loses power, fuel pressure drops to zero. The pressure sensor detects this and sends a signal to the computer. You may see codes like P0087 (fuel rail pressure too low) or P0230 (fuel pump primary circuit malfunction).

What Causes the Relay to Fail

Fuel pump relays fail for a few common reasons:

  • Heat and vibration: The relay sits in the cabin, but it still experiences temperature swings and road vibration. Over thousands of on/off cycles, the internal contacts wear out, burn, or pit.
  • Corrosion: Moisture can get into the fuse box. Corroded terminals add electrical resistance, which makes the relay run hotter and fail sooner.
  • Overload: A failing fuel pump draws more current than normal. That extra load overheats the relay contacts and can eventually melt them or weld them shut.
  • Age: The relay is designed to last the life of the car, but it rarely does. The grueling conditions it operates under take a toll over time.

How to Test the Relay (Before You Buy a New One)

You can confirm a bad relay in a couple of ways without special tools.

The Swap Test:

  1. Locate the fuse panel on the driver's side.
  2. Find the fuel pump relay in position one.
  3. Find another relay in the same panel that looks identical (the horn relay or the MFI relay often match).
  4. Pull the fuel pump relay out and plug the known-good relay into its socket.
  5. Turn the key to "ON" and listen for the fuel pump prime.
  6. If the pump hums now, your original relay is bad.

The Multimeter Test:

If you have a digital multimeter, you can bench-test the relay. Set the meter to measure resistance. Place the probes on terminals 85 and 86. A healthy coil should read between 50 and 120 ohms. A reading of infinite resistance means the internal coil is broken. You can also apply 12 volts to the coil terminals and listen for a click, then check continuity across terminals 30 and 87.

What a New Relay Costs

A new fuel pump relay for a 2007 Eclipse is inexpensive. The part itself costs anywhere from $5 to $20 depending on the brand and where you buy it. If you do the swap yourself, that is your total cost. If you take it to a shop, expect labor to push the total to around $125 to $200.

This is a cheap, quick fix. It is well worth checking the relay before you let a shop talk you into a $400 fuel pump replacement.

When the Relay Is Not the Problem

If you replace the relay and the symptoms continue, the issue lies elsewhere in the fuel system. Check the following:

  1. Fuel pump fuse: Inspect the fuse for a broken filament. A blown fuse is a simpler repair than a relay replacement.
  2. Wiring and connectors: Look for corrosion, broken wires, or damaged electrical connectors in the fuel pump circuit.
  3. The fuel pump itself: A malfunctioning fuel pump can mimic relay symptoms exactly, with hard starting, stalling, and poor performance.
  4. The MFI relay: On the 2007 Eclipse, this relay also controls power to the fuel pump.

A Reliable Replacement Option for the Fuel Pump

If your diagnosis leads you to the fuel pump itself rather than the relay, you want a part that will last. That is where KEMSO Racing comes in.

KEMSO is a brand known for high-performance fuel system components. Their fuel pumps are built as OEM replacements, which means they drop into your 2007 Eclipse with no modification needed. They are designed to meet or exceed the original factory specifications, delivering reliable fuel pressure under all driving conditions.

Every KEMSO fuel pump comes with a lifetime warranty. That gives you peace of mind, because the last thing you want is to install a pump and wonder if it will fail a year down the road.

If you need a fuel pump for your Mitsubishi Eclipse or any other vehicle, visit the KEMSO Racing website at https://www.kemsoracing.com/ to browse their full lineup. They cover a wide range of makes and models, from BMW and KTM motorcycles to Honda and Subaru cars, and everything in between.

Don't Overlook the Simple Stuff

When your 2007 Eclipse refuses to start or stalls mid-drive, the fuel pump relay is a five-minute check that can save you a hundred bucks and a tow truck. The relay is located in the driver's side dash panel, in position one of the fuse box. Listen for the pump prime, swap the relay with a known-good unit, and go from there.

Nine times out of ten, a no-start that cranks but won't fire is an electrical issue, not a mechanical one. Start cheap. Start smart. Replace that relay first, and you will likely have your Eclipse back on the road in under an hour.

If the problem turns out to be the pump itself, remember that KEMSO Racing offers high-performance, OEM replacement fuel pumps with a lifetime warranty. Check out their selection at https://www.kemsoracing.com/ before you make a purchase.


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