Where is the relay fuel pump located?

The fuel pump relay is typically located in the vehicle’s fuse/relay box, most often in the engine bay near the main fuse box. Exact placement varies by make and model, so consult your manual for the precise location.

In most cars, the relay controls the electric fuel pump that pressurizes the fuel system. Some designs place the relay not in the engine bay but in an interior fuse panel, and a few models integrate the pump control directly into the fuel pump assembly in the tank, eliminating a separate relay. The following guide outlines common locations and how to identify them.

Common locations for the fuel pump relay

Many vehicles use a dedicated relay labeled FP, FUEL PUMP, or PUMP in one of the fuse boxes. Here are typical spots to check:

• Engine bay fuse/relay box (power distribution center) close to the battery or along the firewall. Look for a relay labeled FUEL PUMP (FP) or similar.


• Interior fuse box (driver's side dash or under the steering column). The FP relay may be included with other relays here.


• Rear fuse box in some hatchbacks, SUVs, or trucks, often located in the cargo area or near the taillight assemblies.


• Fuel pump module location in the fuel tank (rare in older cars but common in some modern designs). In these setups, the relay may be integrated or located within the module, accessible via the fuel pump wiring harness.


• Some vehicles use the engine control unit (ECU/PCM) to control the pump without a separate relay; in such cases the pump is powered directly by the ECU signal or through a power relay in the main box. Always verify with the service manual.

Interpreting these locations requires checking the fuse box diagrams or the service manual, as labels and board layouts vary by manufacturer and model year.

How to verify and locate on your specific car

Once you know the general locations, follow these steps to confirm the exact spot for your vehicle:

• Consult the owner's manual or the back-panel label on each fuse/relay box for a diagram that lists the FP/FUEL PUMP relay.


• Inspect fuse/relay boxes (engine bay and interior) and identify relays with the same shape/size as known relays; compare to the diagram.


• If safe, swap the FP relay with another identical relay in the box to test; if the pump runs with the other relay, the original may be faulty.


• With ignition on, you should hear the fuel pump prime if the relay is energizing; verify with a multimeter or fuel pressure gauge if needed.

Note: When working near the fuel system, take proper safety precautions, disconnect the battery if wiring work is extensive, and avoid sparks or open flames. If you are unsure, have a professional inspect it.

Conclusion and what to do next

In summary, the relay fuel pump is most often found in the engine bay fuse box, but many vehicles place it in an interior fuse box or integrate it with the fuel pump module in the tank. Always verify with the vehicle's documentation, since placement can vary widely by model and year.

Additional resources

For a precise answer tailored to your car, provide the make, model, and year, and I can point you to the exact location and steps, or help you locate the diagram in your service manual or online repair databases.

Summary: The correct place for the fuel pump relay depends on the vehicle; use the fuse box diagrams in the owner's manual and the service manual to locate it, and verify by ignition testing or swapping relays if safe to do so. If you need, share your vehicle details, and I’ll tailor the guidance.

How do you check if a fuel pump relay is bad?

A bad fuel pump relay can be identified by an engine that cranks but won't start, difficulty starting, engine stalling, or a lack of the usual whirring sound from the fuel pump when the ignition is turned on. Other signs include a check engine light, power loss, engine misfires, hesitation during acceleration, and poor fuel efficiency. You can confirm the issue by using a multimeter to test the relay or by swapping it with a known good relay from your vehicle.
 
This video explains the signs of a bad fuel pump relay: 56sMechanical BoostYouTube · Dec 25, 2024
Key symptoms of a bad fuel pump relay

• Engine cranks but won't start: This is one of the most common signs. The relay fails to send power to the fuel pump, so the engine gets no fuel, even though the starter is turning it over. 
• Difficulty starting or no-start condition: If the relay is failing intermittently, the engine may take several tries to start. A complete failure will prevent the engine from starting at all. 
• Sudden engine stalling: The relay may be cutting off power to the fuel pump unexpectedly while driving, causing the engine to stall. 
• No fuel pump sound: When you turn the key to the "on" position (before cranking), you should hear a faint whirring or buzzing sound from the fuel pump as it builds pressure. If you hear nothing, the relay may be the problem. 
• Check engine light is on: A faulty relay can cause a lean air-fuel mixture, which triggers the check engine light. 
• Engine misfires or rough idle: The inconsistent fuel supply from a bad relay can lead to poor combustion, causing misfires and a rough-running engine. 
• Hesitation or power loss: The engine may hesitate or feel sluggish, especially when under load (like accelerating or going uphill), because the fuel pump is not supplying enough fuel. 

You can watch this video to see how to diagnose a failed fuel pump: 0:481A Auto PartsFacebook · Apr 9, 2024
How to test a fuel pump relay

• Swap with a similar relay: Find another relay in your car's fuse box with the same part number (for a non-critical component like the horn or a similar relay) and swap them. If the fuel pump works with the new relay, the original relay is bad. 
• Use a multimeter: 
  • Set your multimeter to the ohms setting. 
  • Touch the leads to the two power terminals on the relay (often terminals 85 and 86). A good relay will show a resistance value between 50 and 120 ohms. An open circuit or a reading outside this range indicates a bad relay. 
  • Set the multimeter to continuity and listen for a beep. Touch the leads to the two power circuit pins (often 30 and 87) and listen for a beep. If you hear one, the power pins have shorted, and the relay needs to be replaced. 

How to get a fuel pump to kick on?

Use a rubber mallet or the handle of a wrench to gently tap the bottom of the fuel tank. The vibration can sometimes jolt the fuel pump motor back to life, allowing it to pump fuel to the engine.

Where is the fuel pump relay reset?

The fuel pump relay is usually in the fuse box or a relay box. Look under the hood or inside the car. The repair manual or fuse box labels can help you find it.

Where will I find the fuel pump relay?

In most vehicles, the fuel pump relay location is inside the fuse box in the engine bay. This usually looks like a long black box that contains various fuses and relays that enable different parts of your car to function properly.