2021 Chevrolet Silverado 2500HD Fuse Box Diagram & Amperage
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Quick answer
The 2021 Chevrolet Silverado 2500HD has three main fuse box locations: under the hood (engine compartment), inside the cabin (driver's side dash kick panel), and in the rear (under the rear seat on the driver's side).
Under-Hood Fuse Box
The under-hood fuse box is located in the engine compartment, on the driver's side near the battery. This box contains fuses and relays for critical engine functions, lights, and trailer systems. Always refer to the fuse diagram on the inside of the fuse box cover for the most accurate information for your specific trim level.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| F1 | 15A | Blue | ECM/PCM (Engine Control Module/Powertrain Control Module) |
| F2 | 20A | Yellow | Fuel Pump Relay |
| F3 | 10A | Red | Ignition Coils |
| F4 | 30A | Green | Starter Solenoid |
| F5 | 20A | Yellow | Headlight Low Beam (Left) |
| F6 | 20A | Yellow | Headlight Low Beam (Right) |
| F7 | 25A | Clear | Headlight High Beam (Left) |
| F8 | 25A | Clear | Headlight High Beam (Right) |
| F9 | 10A | Red | Tail Lights/Parking Lights (Left) |
| F10 | 10A | Red | Tail Lights/Parking Lights (Right) |
| F11 | 20A | Yellow | ABS Pump/Valve |
| F12 | 15A Blue | Blue | Trailer Brake Controller (Integrated) |
| F13 | 40A | Green | Blower Motor |
| F14 | 10A | Red | A/C Clutch Relay |
| R1 | Relay | Fuel Pump Relay | |
| R2 | Relay | Starter Relay | |
| R3 | Relay | Headlight Low Beam Relay | |
| R4 | Relay | Headlight High Beam Relay | |
| R5 | Relay | A/C Compressor Clutch Relay |
Interior Fuse Box (Driver's Side Dash Kick Panel)
The interior fuse box is located on the driver's side of the dashboard, behind a removable panel near the kick panel. This fuse box primarily handles interior electrical components and accessories.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| F1 | 10A | Red | Radio/Infotainment System |
| F2 | 15A | Blue | HVAC Control Module |
| F3 | 20A | Yellow | Cigar Lighter/12V Power Outlet (Front) |
| F4 | 15A | Blue | Accessory Power Outlet (Console) |
| F5 | 10A | Red | Airbag Module (SIR) |
| F6 | 5A | Tan | Instrument Cluster |
| F7 | 10A | Red | Brake Lights/Stop Lights |
| F8 | 15A | Blue | Power Windows (Driver) |
| F9 | 15A | Blue | Power Windows (Passenger) |
| F10 | 20A | Yellow | Blower Motor Control (HVAC) |
Rear Fuse Box (Under Rear Seat)
Some 2021 Chevrolet Silverado 2500HD models may have an additional fuse box located under the rear seat on the driver's side. This box often houses fuses for rear accessories, power outlets, and certain towing-related circuits.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| F1 | 20A | Yellow | Rear 12V Power Outlet |
| F2 | 30A | Green | Trailer ABS/Battery Charge |
| F3 | 25A | Clear | Rear Seat HVAC |
| F4 | 10A | Red | Trailer Marker Lights |
How to test a fuse
Testing a fuse is a straightforward process that can help you diagnose electrical issues. Here's how to do it:
- Locate the fuse box: Refer to the Quick Answer section to find the correct fuse box.
- Identify the suspected fuse: Use the fuse box diagram (usually located on the inside of the fuse box cover) to find the fuse corresponding to the non-functioning component.
- Visual inspection: Many fuses have a visible wire inside. If this wire is broken or melted, the fuse is blown. However, not all blown fuses are visually obvious, especially the smaller mini-fuses.
- Use a fuse tester or multimeter:
- Fuse Tester: A simple circuit tester with a light can be used. With the ignition on, touch the tester probe to the small metal test points on the top of the fuse. If the light illuminates on both sides, the fuse is good. If it only lights on one side or not at all, the fuse is blown.
- Multimeter: Set your multimeter to read continuity (Ω symbol). Remove the fuse from its slot. Touch the multimeter probes to each metal blade of the fuse. A good fuse will show a very low resistance (close to 0 ohms) or beep if your multimeter has an audible continuity function. An open circuit or
Before you pull a fuse on the 2021 Chevrolet Silverado 2500HD
- Use the label printed on the panel cover or the owner's manual for your exact build. Layouts change with options, model year and build date, so a chart for another truck can be wrong.
- Replace a blown fuse only with the same amp rating. A larger fuse can let wiring overheat.
- A fuse that blows again right away means a short or failing component downstream. Find the cause before replacing it again.
- A good fuse doesn't prove the circuit works — relays, grounds and connectors fail too.
- Disconnect the battery before working near high-current fuses or cables.
Learn more: How fuses, relays and truck electrical systems work
More specs for the 2021 Chevrolet Silverado 2500HD
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Transmission Fluid & Service
Trans model, fluid spec, capacity, filter PN, service interval.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
A/C Refrigerant & Oil
R-134a or R-1234yf, charge oz, PAG oil spec.
Bulb Sizes (Headlight, Tail, Fog)
Headlight, fog, tail, turn, reverse, interior.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
Transmission & Axle Gear Ratios
Trans gear ratios, axle ratios, RPO codes, tow vs MPG impact.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
2001 Silverado 2500HD
2002 Silverado 2500HD
2003 Silverado 2500HD
2004 Silverado 2500HD
2005 Silverado 2500HD
2006 Silverado 2500HD
Maintenance & repair guides
2021 Chevrolet Silverado 2500HD Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
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Values can vary by engine, trim and build date; check your VIN-specific service information. Updated 2026-06-23.