2023 Ford F-350 Super Duty Fuse Box Diagram & Amperage

Quick answer

The 2023 Ford F-350 Super Duty has two main fuse box locations: one under the hood in the engine compartment and another inside the cabin on the passenger side kick panel. There is no fuse box located in the trunk or cargo area of this vehicle.

Under-Hood Fuse Box (Battery Junction Box)

This fuse box is located in the engine compartment, typically near the battery on the driver's side. It houses fuses and relays for critical engine functions, lighting, and other high-current accessories. Always verify the exact fuse layout with the diagram printed on the fuse box lid, as configurations can vary slightly due to trim levels and optional equipment.

Common Relays in the Under-Hood Fuse Box:

• R1: Fuel Pump Relay
• R2: Starter Relay
• R3: PCM/ECM Relay
• R4: Cooling Fan Relay
• R5: A/C Clutch Relay
• R6: Headlight High Beam Relay

Passenger Compartment Fuse Box (Smart Junction Box/Body Control Module)

This fuse box is located on the passenger side of the cabin, behind the kick panel. It manages power distribution for many interior electrical components, infotainment, power accessories, and some body controls. Always consult the diagram printed on the inside of the fuse box cover for the most accurate information regarding your specific vehicle's trim and options.

How to Test a Fuse

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

1. Safety First: Ensure the vehicle's ignition is off and, for the under-hood fuse box, disconnect the battery's negative terminal if you're working on critical circuits.
2. Locate the Fuse: Refer to the fuse box diagram (either in your owner's manual or on the fuse box lid) to identify the suspected fuse.
3. Visual Inspection: Pull the fuse straight out using a fuse puller (usually found in the fuse box) or small needle-nose pliers. Hold it up to the light. A good fuse will have an intact wire or strip between the two prongs. A blown fuse will have a broken or melted wire inside.
4. Use a Multimeter (Recommended): For a more definitive test, set your multimeter to the continuity setting (often indicated by an audible beep or an ohm symbol). Touch the probes to the metal terminals on each end of the fuse. A good fuse will show continuity (the multimeter will beep or display a reading close to zero ohms). A blown fuse will show no continuity ("OL" or open circuit).
5. Replace with Correct Amperage: If the fuse is blown, replace it with a new fuse of the exact same amperage rating and color. Never use a higher-rated fuse, as this can lead to serious electrical damage or fire.
6. Reinstall and Test: Push the new fuse firmly into its slot. Reconnect the battery if disconnected, and test the component that was not working.

Common Blown Fuses on this Vehicle

While fuses can blow for various reasons, some circuits are prone to higher loads or common issues that can lead to a blown fuse on a 2023 Ford F-350 Super Duty:

• Cigar Lighter / 12V Outlets (F22, F23): These fuses often blow due to overloading from charging multiple devices, using high-power accessories, or a faulty accessory itself. If these aren't working, first unplug all devices and check the fuse.
• Trailer Brake Controller (F15): Issues with trailer wiring, a short in the trailer itself, or an improperly connected trailer can cause this fuse to blow. If your trailer brakes aren't working, check the trailer's wiring for any obvious damage or shorts before replacing the fuse.
• Blower Motor (F13): A blower motor that only works on high, or not at all, could indicate a blown fuse or a failing blower motor resistor. If the fuse is blown, it might be a symptom of a blower motor drawing too much current.
• Radio / Infotainment System (F21): While less common, a short in an aftermarket accessory, internal radio fault, or even a sudden power surge can blow this fuse. If your radio is completely dead, this is a good place to start your diagnosis.
• Headlights (F5-F8): While less common to blow fuses frequently in modern vehicles unless there