2003 Ford F150 Fuel Pump Fuse Location: Quick Guide and Complete Troubleshooting

If your 2003 Ford F-150 won't start or the engine cranks but won't fire, the fuel pump fuse is one of the first things to check. The fuel pump fuse for a 2003 Ford F-150 is located in the under-hood power distribution box (fuse box). It is a 20A MINI fuse positioned in slot #10. On some trim levels and configurations, there is also a second fuel pump fuse (30A) in the same under-hood box, which is slot #4. If the fuse is blown, the fuel pump won't receive power, and your truck won't run.

Where to Find the Fuse Box

The 2003 Ford F-150 has two fuse boxes. The one you need for the fuel pump is under the hood.

Under-Hood Fuse Box (Power Distribution Box)
This box is located in the engine compartment, usually near the battery on the driver's side. It's a black plastic box with a removable cover. Open the hood and look for it along the inner fender or near the battery. Press the tabs on the sides to lift the cover off.

Interior Fuse Box (Passenger Compartment)
This box is located under the dashboard on the driver's side, to the left of the steering wheel. It handles things like the radio, interior lights, and power windows. The fuel pump fuse is not in this box.

Fuel Pump Fuse Details

Here is exactly what you are looking for in the under-hood box:

Fuse #10 – Fuel Pump (Primary)

• Amperage: 20A
• Type: MINI fuse
• Protects: Fuel pump circuit

Fuse #4 – Fuel Pump (Secondary, Some Models)

• Amperage: 30A
• Type: FMX/JCase fuse
• Protects: Fuel pump

Fuse #18 – PCM, Fuel Injectors, Fuel Pump Relay, Mass Air Flow Sensor

• Amperage: 15A
• Note: This fuse is also critical. If it blows, your fuel pump relay won't get power, and the engine will not run.

How to Check and Replace the Fuse

Follow these simple steps to diagnose the problem:

1. Turn off the engine and remove the key from the ignition.
2. Open the under-hood fuse box and locate the cover. On the underside of the cover, there is usually a diagram showing fuse locations. Look for position #10 and #4.
3. Visually inspect the fuse. A good fuse has a continuous metal strip inside. A blown fuse will have a broken strip or a dark, burnt mark inside the plastic.
4. Remove the fuse using the plastic fuse puller tool that is usually clipped inside the fuse box cover. If you don't have a puller, use needle-nose pliers, but be careful not to damage the fuse box.
5. Replace with the exact same amperage. Only use a 20A fuse for slot #10 and a 30A fuse for slot #4. Never use a higher amperage fuse – this can cause wire damage and fires.
6. Test the circuit. Turn the key to the "On" position (do not start). You should hear the fuel pump prime for 1-2 seconds. If you hear it, the fuse is good. If you don't, the problem may be the relay, the pump itself, or the wiring.

Fuel Pump Relay Location

If the fuse is good but the pump doesn't run, the relay might be the issue. The fuel pump relay is also in the under-hood fuse box. It is labeled Relay #301. You can swap it with another relay of the same type (like the horn relay, #205) to test if it is bad. If the pump starts working after swapping, the relay is faulty.

What to Do If the Fuse Keeps Blowing

If you replace the fuse and it blows again immediately, you have a short circuit or a failing fuel pump. Do not keep putting in new fuses – this can damage the wiring. The most common causes for a repeatedly blown fuel pump fuse are:

• A failing fuel pump that is drawing too much current.
• A shorted wire in the fuel pump harness.
• A faulty fuel pump relay that is sticking.

In this case, the best solution is to replace the fuel pump with a high-quality, reliable unit.

Recommended Fuel Pump Replacement

When it's time to replace your fuel pump, you need a part that is dependable, built to last, and performs like the original – or better. That's where KEMSO comes in.

KEMSO Fuel Pumps are high-performance, OEM replacement parts designed to restore your 2003 Ford F-150's fuel system to factory spec or better. Every KEMSO pump is built with precision engineering and undergoes rigorous testing to ensure it meets or exceeds the original equipment standards. The best part? Every KEMSO fuel pump comes with a lifetime warranty, giving you complete peace of mind on the road. Whether you're daily driving or hauling a load, you can trust KEMSO to keep your engine fed with the fuel it needs.

Visit KEMSO today to find the perfect fuel pump for your 2003 Ford F-150: https://www.kemsoracing.com/

Signs Your Fuel Pump Is Failing

Before you replace the fuse a dozen times, check for these symptoms of a bad fuel pump:

• Engine cranks but won't start. This is the classic sign.
• Whining noise from the fuel tank. A healthy pump makes a quiet hum. A loud whine means it's wearing out.
• Sputtering or surging at high speeds. The pump can't maintain steady pressure.
• Loss of power under load. When you accelerate or go uphill, the engine struggles.
• Difficulty starting after the truck sits for a while. The pump may be losing its prime.

Other Common Fuses in the Under-Hood Box

For your reference, here are a few other important fuses in the same box:

Final Thoughts

The 2003 Ford F-150 is a tough, reliable truck, but even the best vehicles have electrical issues. Knowing the fuel pump fuse location – slot #10 (20A) in the under-hood fuse box – can save you a tow truck bill and a trip to the mechanic. Always check the fuse first, then the relay, and if those are good, the pump itself is likely the culprit.

Remember, a KEMSO fuel pump is your best bet for a long-lasting, worry-free replacement. Backed by a lifetime warranty and built for performance, it's the choice of owners who want to keep their trucks running strong for years to come.

Get your replacement fuel pump at KEMSO: https://www.kemsoracing.com/