2021 Ram 2500 – Fuse Box Diagram & Amperage

Quick Answer

The 2021 Ram 2500 has three main fuse box locations: the Power Distribution Center (PDC) under the hood, the Interior Fuse Box (IFB) in the passenger footwell, and an Auxiliary Fuse Box (AFB) for certain accessories, often found in the rear cargo area or under the rear seat depending on the trim and options.

Under-Hood Power Distribution Center (PDC)

The Power Distribution Center (PDC) is located in the engine compartment, typically near the battery on the driver's side. It houses high-current fuses and relays for major vehicle systems. Always consult the lid of your PDC for the most accurate diagram, as configurations can vary slightly by trim and installed options.

Relay Locations (PDC):

• R1: Starter Relay
• R2: Fuel Pump Relay
• R3: HVAC Blower Motor Relay
• R4: A/C Clutch Relay
• R5: Headlight Low Beam Relay
• R6: Headlight High Beam Relay
• R7: Trailer Tow Park Lamp Relay
• R8: Trailer Tow Left Turn Relay
• R9: Trailer Tow Right Turn Relay

Interior Fuse Box (IFB)

The Interior Fuse Box (IFB) is located in the passenger footwell, typically behind a panel on the right kick panel or glove box access. This fuse box protects many of the lower-current accessories and interior components.

Auxiliary Fuse Box (AFB)

Some 2021 Ram 2500 trims, particularly those with upfitter switches, or certain premium audio/accessory packages, may include an auxiliary fuse box. This is often located in the rear cargo area, under the rear seat, or behind a side panel depending on the cab configuration and specific options. Consult your owner's manual for the exact location if your vehicle is equipped with one.

How to Test a Fuse

1. Locate the Fuse: Remove the fuse box cover and identify the fuse in question using the diagram (either on the lid or in this guide). Always turn off the ignition and any affected circuits before testing.
2. Visual Inspection: Many fuses have a visible wire element inside. If this wire is broken or melted, the fuse is blown. However, not all blown fuses are visually obvious, especially with mini-fuses.
3. Use a Test Light or Multimeter:
   • Test Light: With the ignition on (or the specific circuit energized if safe), touch one end of the test light to a known ground point and the other end to the two small metal test points on top of the fuse. If the test light illuminates on both sides, the fuse is good. If it only illuminates on one side or not at all, the fuse is blown.
   • Multimeter: Set your multimeter to the continuity or ohms setting. Remove the fuse from its slot. Touch the multimeter probes to each metal blade of the fuse. A good fuse will show very low resistance (close to 0 ohms) or beep for continuity. A blown fuse will show an open circuit (OL or infinite resistance).
4. Replace if Blown: If the fuse is blown, replace it with a new fuse of the exact same amperage rating and type. Using a fuse with a higher amperage can cause severe electrical damage or even a fire.

Common Blown Fuses on this Vehicle

While fuses can blow for various reasons, some are more common on a 2021 Ram 2500 due to their usage or the components they protect.

• Cigar Lighter / 12V Outlets (F31, F32): These fuses often blow due to overloading from charging multiple devices or using high-power accessories. Check for faulty charging cables or accessories as a primary cause.
• Trailer Brake Control (F03, F53): Issues with trailer wiring or a short in the trailer