2018 Chevrolet Silverado 2500HD – Fuse Box Diagram & Amperage

Quick Answer

The 2018 Chevrolet Silverado 2500HD features three main fuse box locations:

• Under-hood Fuse Box: Located in the engine compartment on the driver's side, near the battery.
• Instrument Panel Fuse Box: Situated on the passenger side of the dashboard, behind a removable panel.
• Rear Under Seat Fuse Box: Found under the rear seat on the driver's side.

Under-hood Fuse Box

The under-hood fuse box is the primary distribution point for many critical engine and high-current circuits. Always disconnect the battery before servicing fuses in this box.

Relay Locations (Under-hood):

• RL1: Fuel Pump Relay
• RL2: Starter Relay
• RL3: Run/Crank Relay
• RL4: HVAC Blower Motor Relay
• RL5: A/C Clutch Relay
• RL6: Headlight High Beam Relay (Left)
• RL7: Headlight High Beam Relay (Right)
• RL8: Headlight Low Beam Relay (Left)
• RL9: Headlight Low Beam Relay (Right)

Note: Relay locations are typically marked on the underside of the fuse box cover. Always refer to your vehicle's specific legend for exact identification.

Instrument Panel Fuse Box

The instrument panel fuse box primarily handles interior electrical components and accessories. It's often located behind a removable access panel on the passenger side dashboard.

Relay Locations (Instrument Panel):

• RL1: Accessory Delay Relay
• RL2: Wiper Control Relay

Note: The exact number of fuses and their assignments can vary slightly based on your Silverado's specific trim level and options. Always cross-reference with the diagram printed on the inside of your fuse box cover or your owner's manual.

Rear Under Seat Fuse Box

This fuse box often provides power to rear accessories, trailer connections, and other high-demand components often found on heavy-duty trucks.

Note: The location may vary slightly. On some models, this fuse box might be located under the center console or in the rear cargo area, depending on a specific trim or options package.

How to Test a Fuse

Testing a fuse is a straightforward process. Here's how to do it safely and effectively:

1. Locate the Fuse Box: Identify the correct fuse box for the circuit you're troubleshooting.
2. Turn Off the Vehicle: Ensure the ignition is off and, for under-hood fuses, it's wise to disconnect the battery's negative terminal.
3. Identify the Suspect Fuse: Refer to the fuse box diagram (either in this guide or on your fuse box cover) to find the fuse for the malfunctioning component.
4. Visually Inspect: Many fuses (especially mini and ATO blade fuses) have a clear plastic body. Look for a broken wire or blackened area inside the fuse. If it's broken, the fuse is blown.
5. Use a Multimeter or Fuse Tester: For a more reliable test, especially if a visual inspection is inconclusive, use a multimeter set to continuity mode or a dedicated fuse tester. Touch the probes to the two metal test points 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 continuity or an