2025 Ford F-350 Super Duty Fuse Box Diagram & Amperage

Quick Answer

The 2025 Ford F-350 Super Duty typically features three main fuse box locations: one under the hood, a second inside the cabin on the passenger side kick panel, and a third in the rear cargo area/trunk, usually on the passenger side.

Under-Hood Fuse Box

The under-hood fuse box, also known as the Power Distribution Box, is located in the engine compartment, usually near the battery on the driver's side. It houses high-amperage fuses and relays for critical engine functions, lights, and other major electrical components.

Under-Hood Relays:

• R1: Fuel Pump Relay
• R2: Starter Relay
• R3: PCM Relay
• R4: Headlight Relay
• R5: Blower Motor Relay

Passenger Compartment Fuse Box (Kick Panel)

This fuse box, also known as the Smart Junction Box (SJB) or Body Control Module (BCM), is typically located behind a panel on the passenger side kick panel, near the floorboard. It controls various interior electrical systems, accessories, and body functions.

Rear Cargo Area/Trunk Fuse Box

The rear fuse box, sometimes referred to as the "Trailer Fuse Box" or "Auxiliary Power Distribution Box," is typically located in the rear cargo area, often behind a removable panel on the passenger side. This box often handles power for rear accessories, trailer connections, and specialized equipment.

How to Test a Fuse

Testing a fuse is a straightforward process that can save you time and money. Here's how:

1. Locate the Fuse Box: Refer to your owner's manual or the quick answer section above to find the correct fuse box.
2. Identify the Suspect Fuse: Look at the fuse box diagram (either printed on the inside of the fuse box cover or in your owner's manual) to find the fuse associated with the malfunctioning component.
3. Visual Inspection: Many fuses have a clear plastic body. You can often see if the metal wire inside is broken or melted. If it is, the fuse is blown and needs to be replaced.
4. Use a Fuse Tester (Recommended): For fuses where a visual inspection isn't clear, or for cartridge-style fuses, a fuse tester is invaluable. With the ignition off, touch the probes of the tester to the two small metal test points on the top of the fuse. If the tester lights up on both sides, the fuse is good. If it only lights up on one side or not at all, the fuse is blown.
5. Remove and Replace: Carefully pull the blown fuse straight out using a fuse puller (usually found in the fuse box or tool kit) or small needle-nose pliers. Insert a new fuse of the exact same amperage rating and type. Never use a fuse with a higher amperage rating, as this can lead to serious electrical damage or fire.

Common Blown Fuses on This Vehicle

While any fuse can blow, some are more commonly affected due to their circuits or usage. On a 2025 Ford F-350 Super Duty, you might frequently encounter issues with:

• Trailer Brake Control (F13 Under-Hood, F4 Rear): Given the F-350's towing capabilities, trailer-related fuses can blow due to short circuits in trailer wiring or heavy loads. Always check your trailer's wiring for damage before suspecting the fuse.
• Cigar Lighter/Power Outlets (F2, F3 Passenger Compartment): These fuses often blow when too many high-power accessories are plugged in, or if there's a short in a connected device. Remove all accessories before replacing the fuse.
• Blower Motor (F10 Under-Hood): A failing blower motor or an obstruction in the HVAC system can cause the blower motor fuse to blow. If the fuse blows repeatedly, have the blower motor and its circuit inspected.
• Headlights (F5, F6, F7, F8 Under-Hood): While less common with modern LED lighting, a short in the headlight wiring or a faulty bulb (if applicable) can still cause these fuses to blow.
• Radio/Infotainment (F1 Passenger Compartment): Issues with aftermarket installations, a faulty head unit, or even a short in an auxiliary device can cause this fuse to blow.

When a fuse blows, always try to determine the underlying cause. Simply replacing a fuse without addressing the root problem will likely result in the new fuse blowing again.

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