August 2026

2013 F150 5.0 Fuel Pump Relay Location: Where to Find It and How to Fix It

The fuel pump relay on your 2013 Ford F-150 with the 5.0L V8 engine is located inside the Power Distribution Box (PDB) under the hood, on the passenger side near the firewall. The relay is labeled as position number 8 in the PDB, and it works together with fuse 27 (a 20-amp mini fuse) to supply power to the fuel pump. If you're dealing with a no-start condition, intermittent stalling, or loss of power while driving, the fuel pump relay is one of the first things you should check before moving on to more expensive repairs.

Finding the Power Distribution Box on Your 5.0L F-150

For the 2013 F-150 with the 5.0L Ti-VCT V8 engine, the Power Distribution Box is located on the passenger side of the engine bay, close to the firewall. This is the same location used for the 3.7L V6 and 6.2L Boss V8 engines. If you have the 3.5L EcoBoost engine, the PDB is on the driver's side instead.

Once you pop the hood, look toward the passenger side where the engine meets the firewall. You'll see a black plastic box with a removable cover. The cover has a diagram printed on its underside that shows the exact location of every fuse and relay in the box. If the diagram is faded or missing, you can check your owner's manual or snap a photo of the diagram before removing anything so you can put everything back correctly.

Identifying the Fuel Pump Relay and Fuse

Inside the Power Distribution Box, the fuel pump relay is position number 8. It is a standard automotive relay, typically colored black or gray, with either 4 or 5 pins. The relay controls the power flow to the fuel pump, and it works together with a dedicated fuse.

Here is what you need to know about the specific components:

1. Relay 8: Fuel Pump Relay – This is the main relay that controls power to the fuel pump. When you turn the ignition key to the "ON" position, the relay closes and sends power to the pump. If the relay fails, the pump won't get power and the engine won't start.

2. Fuse 27 (20A MINI): Fuel Pump Relay Power – This 20-amp mini fuse supplies power to the relay coil and the fuel pump circuit. If the relay is good but the fuse is blown, the fuel pump will not receive power. Before pulling the relay, inspect fuse 27. If it looks blown (the metal strip inside is broken), replace it with a 20A mini fuse. If the new fuse blows immediately, you likely have a short circuit somewhere in the fuel pump wiring.

Symptoms of a Bad Fuel Pump Relay

A failing fuel pump relay can cause several distinct problems. Recognizing these symptoms early can save you from being stranded. Common symptoms include:

1. Engine cranks but won't start – This is the most obvious symptom. You turn the key, the starter engages and the engine cranks, but it never fires up. The fuel pump is not receiving power because the relay is not closing the circuit.

2. Intermittent stalling – The engine may run fine for a while, then suddenly die without warning. After sitting for a few minutes, it might restart, only to stall again later. This is often caused by a relay that fails when it gets hot.

3. Loss of power under load – If the relay is making poor contact, the fuel pump may not get full voltage. This can cause the engine to hesitate or lose power when you accelerate, especially when towing or climbing hills.

4. No fuel pump noise – When you turn the ignition key to the "ON" position (before cranking), you should hear a brief humming sound from the fuel tank area near the rear of the truck. This is the fuel pump priming. If you hear nothing, the relay may not be sending power to the pump.

5. Check Engine Light – In some cases, a failing relay can trigger diagnostic trouble codes such as P0232 (Fuel Pump Secondary Circuit High). This code indicates an electrical problem in the fuel pump control circuit.

How to Test the Fuel Pump Relay

Before buying a new relay, you can test the existing one with basic tools. Here is a step-by-step method that works for most DIYers:

Step 1: Locate the relay – Find relay 8 in the Power Distribution Box on the passenger side near the firewall.

Step 2: Listen for the click – Have a helper turn the ignition key to the "ON" position (not start) while you place your hand on the relay. You should feel and hear a distinct click as the relay energizes. If you don't hear anything, the relay may not be receiving a signal or could be faulty.

Step 3: Swap the relay – The easiest test is to swap the fuel pump relay with another relay of the same type and rating from a non-critical system, like the horn or wiper relay. If the fuel pump starts working after the swap, the original relay is bad.

Step 4: Use a multimeter – If you have a multimeter, you can test for continuity and voltage. With the relay removed, check for resistance across the coil terminals. A good relay typically shows 50-120 ohms. Then, with the relay plugged in and the ignition on, check for 12V at the output terminal.

Common Causes of Fuel Pump Relay Failure

Understanding why the relay fails can help you prevent future issues. The most common causes include:

Current overload – If the fuel pump or the electrical system is drawing more current than the relay is designed to handle, the relay contacts can overheat and burn out.

Short circuit – A short circuit in the electrical system can cause a current overload through the relay, which can burn the contacts or damage the relay's coil.

Defective internal components – Over time, the internal components of the relay, such as the electromagnetic coil or mechanical contacts, can wear out or fail due to repeated use, vibrations, or simply the age of the component.

Other Possible Causes of Fuel Pump Failure

If the relay is functioning correctly, other possible causes of fuel pump failure include:

Blown fuse – The fuse protecting the fuel pump relay, or the fuel pump fuse itself, may be blown. This usually happens due to an electrical problem, such as a damaged wire coming into contact with the vehicle's body.

Impact sensor activation – Some vehicles are equipped with an impact sensor, also known as an inertia switch, that cuts off power to the fuel pump in case of an accident. If this sensor is activated, the pump will stop operating.

Engine control unit issues – The ECU manages various vehicle functions, including the operation of the fuel pump. A failure in the ECU or in the sensors that send data to it can affect the pump's operation.

Clogged fuel filter – A very dirty or blocked filter can reduce fuel flow, causing the pump to work harder, which can lead to its failure.

Fuel pressure problems – A faulty fuel pressure regulator or an obstruction in the fuel line can hinder proper fuel delivery.

Wiring problems – Damaged, corroded, or loose wires can prevent the pump from receiving the necessary power to operate.

Defective fuel pump – The pump itself may be failing due to wear, internal damage to its components, or manufacturing defects.

Final Thoughts

The fuel pump relay on your 2013 F-150 5.0L is easy to find once you know where to look. Start by checking the Power Distribution Box on the passenger side near the firewall. Look for relay position number 8 and fuse 27. Test the relay by listening for the click, swapping it with another relay, or using a multimeter. If the relay is bad, replace it with a standard automotive relay. If the problem persists, check the fuse, wiring, and other components before moving on to the fuel pump itself.

Keep a spare relay in your glove box, and always consult your owner's manual for specific details about your truck. With the right approach, you can diagnose and fix fuel pump relay issues quickly and get back on the road.

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