2018 Ram 1500 Fuse Box Diagram & Amperage

Quick answer

The 2018 Ram 1500 typically has three fuse box locations: the Power Distribution Center (PDC) under the hood, an interior fuse box located on the passenger side kick panel, and a rear fuse box often found behind the passenger seat or under the rear bench seat, usually in models with a Mega Cab or extensive rear electrical options. Always consult your owner's manual and the fuse diagrams printed on the fuse box lids for the most accurate and trim-specific information.

Under-Hood Power Distribution Center (PDC)

The Power Distribution Center (PDC) is located in the engine compartment, usually near the battery on the driver's side. This box contains high-current fuses and relays for major electrical components.

Relays in the PDC:

• R1: Starter Relay
• R2: Fuel Pump Relay
• R3: Horn Relay
• R4: A/C Clutch Relay
• R5: Blower Motor Relay
• R6: Headlight High Beam Relay
• R7: Headlight Low Beam Relay
• R8: Trailer Tow Battery Charge Relay
• R9: Wiper Motor Relay

Interior Fuse Box (Passenger Side Kick Panel)

The interior fuse box is located on the passenger side of the cabin, behind the kick panel. This box contains fuses for various interior electrical components.

Rear Fuse Box (If Equipped)

Some 2018 Ram 1500 models, particularly those with a Mega Cab or specific option packages, may have an additional fuse box located in the rear of the vehicle. This is often behind the passenger-side rear seat or under the rear bench seat. Always check your owner's manual for exact placement.

How to test a fuse

Testing a fuse is a straightforward process that requires a fuse puller (usually found in your fuse box lid) and a multimeter or a fuse test light.

1. Locate the suspected fuse: Refer to the diagrams above and your vehicle's fuse box legend to identify the fuse for the component that isn't working.
2. Turn off the ignition: Always ensure the vehicle is off and the key is removed to prevent electrical shocks or short circuits.
3. Remove the fuse: Use the fuse puller to carefully remove the fuse from its slot.
4. Visually inspect the fuse: Hold the fuse up to a light. If the metal wire inside is broken or burnt, the fuse is blown and needs to be replaced.
5. Test with a multimeter (recommended):
   • Set your multimeter to the continuity setting (often indicated by a speaker icon). If it beeps, there's continuity.
   • Touch the probes of the multimeter to the two metal prongs on top of the fuse. If the multimeter beeps or shows a reading close to zero ohms, the fuse is good. If there's no beep or an "OL" (open loop) reading, the fuse is blown.
6. Test with a fuse test light:
   • Connect the alligator clip of the test light to a good ground point on the vehicle's chassis.
   • With the ignition on (but engine off), touch the tip of the test light to the small metal test points on top of the fuse. The light should illuminate on both sides if the fuse is good. If it only illuminates on one side or not at all, the fuse is blown.
7. Replace the fuse: If the fuse is blown, replace it with a new fuse of the exact same amperage rating and type. Never use a fuse with a higher amperage rating, as this can cause severe damage to your vehicle's electrical system or even a fire.

Common blown fuses on this vehicle

While fuses can blow for various reasons, some circuits on the 2018 Ram 1500 might be more prone to issues due to their usage or load. If you experience a problem, check these first:

• Cigar Lighter / 12V Outlets (F30, F31): These frequently blow due to overloads from charging multiple devices or using high-power accessories. Check if you're plugging in too many devices or if a connected device is faulty.
• Trailer Brake Control / Trailer Tow Battery Charge (F20, F03): If you frequently tow, these fuses can blow due to issues with the trailer's wiring, electrical shorts on the trailer, or overloading the trailer's electrical system. Inspect your trailer wiring and connections.
• Headlights (F13, F14, F15, F16): While less common, a short in a headlight bulb or wiring can cause these fuses to blow. If a single headlight goes out, check its dedicated fuse.
• Blower Motor (F04): A failing blower motor or a blockage in the HVAC system forcing the motor to work harder can cause this fuse to blow. If your fan suddenly stops working, this is a prime suspect.
• Radio / Infotainment (F32): Although not as common, issues with aftermarket installations, wiring shorts, or internal unit faults can cause this fuse to blow, leading to your radio not turning on.

Always remember to check the fuses with the associated component first. For instance, if your stereo isn't working, check the radio fuse. If multiple components are out, especially those in the same fuse box, it might indicate a larger electrical issue or a main power fuse that has blown.

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