2021 Ford Ranger Fuse Box Diagram & Amperage

Quick answer

The 2021 Ford Ranger has three main fuse box locations: under the hood, behind the passenger side kick panel (dashboard), and in the rear of the vehicle (often behind a trim panel in the cargo area).

Under-Hood Fuse Box (Battery Junction Box - BJB)

The under-hood fuse box, also known as the Battery Junction Box (BJB), is located on the passenger side of the engine compartment, near the battery. It contains high-current fuses and relays for major electrical components.

Relay Locations (Under-Hood BJB):

• R1: Powertrain Control Module (PCM) Relay
• R2: Fuel Pump Relay
• R3: Starter Relay
• R4: Cooling Fan Relay
• R5: A/C Clutch Relay

Passenger Compartment Fuse Box (Smart Junction Box - SJB)

The passenger compartment fuse box, also known as the Smart Junction Box (SJB), is located behind the passenger side kick panel, next to the glove box. You'll need to remove the kick panel to access it. This box controls many interior electrical features.

Rear Fuse Box / Trunk/Cargo Area Fuse Box

Depending on your specific trim level and options, some 2021 Ford Ranger models may have an additional fuse box located in the rear of the vehicle, often behind a trim panel in the cargo area or under the rear seats. This box typically handles circuits for rear accessories or trailer components.

How to test a fuse

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

1. Safety First: Always turn off the ignition and remove the key (or ensure the vehicle is off and in park) before working with fuses.
2. Locate the Fuse Box: Refer to your owner's manual or the quick answer section above to find the correct fuse box.
3. Identify the Suspect Fuse: Look at the fuse box lid or your owner's manual to find the fuse for the component that isn't working.
4. Visual Inspection: Most modern fuses have a visible wire inside. If this wire is broken or melted, the fuse is blown. You can often see through the clear plastic body of the fuse.
5. Use a Fuse Tester (Recommended): For a more definitive test, use a fuse tester or a multimeter. With the ignition off, touch the tester probes to the two small metal test points on the top of the fuse. If the tester lights up (or the multimeter shows continuity), the fuse is good. If not, it's blown.
6. Replace the Fuse: If you find a blown fuse, replace it with a new fuse of the exact same amperage rating and color. Never use a fuse with a higher amperage, as this can cause serious electrical damage or even a fire.

Common blown fuses on this vehicle

While fuses can blow for various reasons, some common ones on the 2021 Ford Ranger (and many modern vehicles) include:

• Cigar Lighter / 12V Outlets: These fuses (F21 and F14) often blow due to overcurrent from charging multiple devices or using high-power accessories. If your phone charger or dash cam suddenly stops working, check these first.
• Headlight Fuses: If one of your headlights goes out, check the respective low or high beam fuse (F7, F8, F9, F10) in the under-hood box. Sometimes an aging bulb can draw too much current before failing, or a short in the wiring can cause these to blow.
• Radio/Infotainment System: If your radio suddenly goes dark or loses power, check fuse F20 in the passenger compartment fuse box. A short circuit in an aftermarket accessory or an internal fault in the radio itself can be the cause.
• Trailer Brake Controller / Trailer Tow: If you experience issues with your trailer lights or brakes, check the relevant fuses in the under-hood or rear fuse boxes (F13, F40, F42, F43). Towing heavy loads or issues with trailer wiring can often cause these to blow.

Remember, if a fuse blows repeatedly, there's likely an underlying electrical issue that needs to be diagnosed by a professional. Always verify the printed legend in your specific fuse box lid, as configurations can vary slightly due to trim levels and optional equipment.

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