2019 Chevrolet Silverado 3500HD Fuse Box Diagram & Amperage

Quick Answer

The 2019 Chevrolet Silverado 3500HD typically has three fuse box locations: under the hood (engine compartment), inside the cabin (driver's side kick panel), and in the rear (under the rear seat or in the cargo area).

Under-Hood Fuse Box (Engine Compartment Fuse Block)

This fuse box is located in the engine compartment, usually on the driver's side, near the battery. It contains fuses and relays for critical engine functions, lighting, and other high-current accessories.

Always verify the exact fuse configuration with the diagram printed on the fuse box cover, as variations can occur based on trim level and options.

Relay Locations (Under-Hood):

• RL1 (Starter Relay): Engages the starter motor.
• RL2 (Fuel Pump Relay): Powers the fuel pump.
• RL3 (Run/Crank Relay): Powers various ignition and engine components.
• RL4 (Blower Motor Relay): Powers the blower motor for HVAC.
• RL5 (Headlight Low Beam Relay): Controls low beam headlights.
• RL6 (Headlight High Beam Relay): Controls high beam headlights.
• RL7 (A/C Clutch Relay): Powers the A/C compressor clutch.

Instrument Panel Fuse Box (Interior Fuse Block)

This fuse box is typically located on the driver's side, behind a panel on the side of the dashboard (kick panel). It houses fuses for interior electrical components, infotainment, power accessories, and some body control modules.

Rear Under-Seat / Cargo Area Fuse Box (Body Fuse Block)

This fuse box is often found under the rear seat or in the cargo area on the 2019 Silverado 3500HD, particularly in crew cab models. It manages power for some rear accessories, trailer wiring, and additional body systems.

Note: Actual fuse numbers and circuits may vary slightly based on specific vehicle configuration, trim level, and options (e.g., HD trucks often have more extensive trailer-related fusing). Always refer to the fuse diagram provided in your owner's manual or on the fuse box cover for the most accurate information for your specific vehicle.

How to Test a Fuse

Testing a fuse is a straightforward process:

1. Locate the Fuse Box: Identify the correct fuse box for the circuit you're troubleshooting.
2. Identify the Suspect Fuse: Consult the fuse box diagram to find the fuse for the component that isn't working.
3. Visual Inspection: Most automotive fuses have a small wire or metal strip visible through a clear plastic body. If this wire is broken or melted, the fuse is blown.
4. Use a Fuse Tester or Multimeter: For a more definitive test, especially with opaque fuses or if the break is not obvious:
   • Fuse Tester: Insert the fuse into the tester. If the light illuminates, the fuse is good. If not, it's blown.
   • Multimeter: Set the multimeter to the continuity or ohms setting. Remove the fuse from its slot. Touch the probes to the metal terminals on top of the fuse. A good fuse will show very low resistance or continuity (the multimeter may beep). A blown fuse will show infinite resistance or an open circuit (no beep).
5. Replace if Blown: If the fuse is blown, replace it with a new fuse of the exact same amperage rating (and color). Never use a fuse with a higher amperage rating, as this can lead to serious electrical damage or fire.

Common Blown Fuses on This Vehicle

While any fuse can blow, certain circuits are more prone to issues due to their load or common accessory use. On a 2019 Chevrolet Silverado 3500HD, common culprits include:

• Cigar Lighter / 12V Power Outlets (Interior Fuse Box): These fuses (F2, F3, F1 in the rear box) often blow when too many accessories are plugged in, or there's a short circuit from a faulty device. If your phone charger or air compressor stops working, check these first.
• Trailer Brake Controller / Trailer Auxiliary (Under-Hood and Rear Fuse Box): Given this is a 3500HD, these circuits (F15, F16, F17 under-hood; F2, F3, F4 in the rear) are heavily used. Overloading a trailer's electrical system or a short in the trailer's wiring can easily blow these fuses. If your trailer lights or brakes aren't working, these are prime suspects.
• Blower Motor (Under-Hood Fuse Box): The blower motor (F13) draws a lot of current, especially on higher settings. If your A/C or heat fan stops working entirely, this fuse might be the cause, or less commonly, the blower motor itself.
• Headlights (Under-Hood Fuse Box): While less common with modern sealed-beam or LED units, if a single headlight or a pair of high/low beams go out (F5, F6, F7, F8), check these fuses first. A short in the wiring or a faulty bulb (if applicable) can sometimes pop them.

When a fuse blows, it's a symptom, not always the root cause. If a fuse blows repeatedly, there's an underlying electrical issue that needs professional diagnosis, such as a short circuit, an overloaded circuit, or a faulty component.

Find a trusted shop on Repairius.