2020 GMC Sierra 1500 Fuse Box Diagram & Amperage
Complete guide to the fuse locations, diagrams, and common issues for the 2020 GMC Sierra 1500, including under-hood and in-dash panels.
AI-generated reference. Always verify torque values, fluid capacities, intervals, and procedures against the manufacturer's service manual or OEM repair information before performing work. Repairius is not liable for damage from acting on this content without verification.
Working on this 2020 GMC Sierra 1500? Run just this one job through Repairius.
No big switch. Write the estimate, text it for approval, and get paid on your phone. Keep everything else the way it is.
14-day free trial · credit card required · cancel anytime
Quick Answer
The 2020 GMC Sierra 1500 has two primary fuse box locations:
- Engine Compartment Fuse Block: Located on the driver's side of the engine bay, near the battery.
- Instrument Panel Fuse Block: Located on the driver's side of the dashboard, accessible when the driver's door is open.
Important Note: Always verify the fuse information with the diagram printed on the inside of your fuse box cover. Fuse assignments can vary based on your truck's specific trim level and options (e.g., SLE, SLT, Denali, AT4).
Engine Compartment Fuse Block
This fuse block contains higher-amperage fuses and relays that control major systems like the engine, transmission, fuel system, and lighting. To access it, open the hood and locate the black plastic cover on the driver's side.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| F1 | 60A | Yellow | Instrument Panel Fuse Block |
| F2 | 40A | Green | Blower Motor |
| F5 | 30A | Pink | Starter Motor |
| F7 | 20A | Yellow | Left High-Intensity Discharge Headlamp |
| F8 | 20A | Yellow | Right High-Intensity Discharge Headlamp |
| F10 | 15A | Blue | Engine Control Module (ECM) / Powertrain Control Module (PCM) - Ignition |
| F12 | 20A | Yellow | Fuel Pump |
| F14 | 15A | Blue | Ignition Coils (Odd) |
| F15 | 15A | Blue | Ignition Coils (Even) |
| F22 | 25A | Natural | A/C Clutch Relay |
| F24 | 30A | Pink | Trailer Brake Control Module |
| F26 | 25A | Natural | Antilock Brake System (ABS) Pump |
| F27 | 10A | Red | Antilock Brake System (ABS) Module |
| F31 | 15A | Blue | Left Low Beam Headlamp |
| F32 | 15A | Blue | Right Low Beam Headlamp |
| F33 | 10A | Red | Left Tail/Park Lamp |
| F34 | 10A | Red | Right Tail/Park Lamp |
| F40 | 10A | Red | ECM / PCM |
| F44 | 10A | Red | Airbag / Supplemental Inflatable Restraints (SIR) |
Relay Locations (Engine Compartment)
- KR1: Starter Relay
- KR4: A/C Clutch Relay
- KR5: Run/Crank Relay
- KR10: Fuel Pump Relay
- KR11: Powertrain Relay
Instrument Panel Fuse Block
This fuse block is located on the left side of the instrument panel, accessible by opening the driver's door and removing the side panel. It primarily protects interior circuits and components.
| Fuse # | Amp | Color | Circuit / Component Protected |
|---|---|---|---|
| F1 | 10A | Red | Airbag System |
| F4 | 10A | Red | Instrument Cluster |
| F10 | 15A | Blue | Radio / Infotainment System |
| F12 | 15A | Blue | OnStar Module |
| F17 | 10A | Red | Steering Wheel Controls |
| F18 | 20A | Yellow | Cigar Lighter / 12V Power Outlet (Instrument Panel) |
| F19 | 20A | Yellow | 12V Power Outlet (Center Console) |
| F29 | 10A | Red | Body Control Module (BCM) |
| F32 | 10A | Red | Brake Switch / Stop Lamps |
| F33 | 2A | Gray | HVAC Controls |
| F36 | 15A | Blue | Wireless Charger |
How to Test a Fuse
Testing a fuse is a simple process. A "blown" fuse has a broken internal wire, interrupting the electrical circuit it's meant to protect.
- Turn the ignition off.
- Locate and remove the suspect fuse. Most fuse boxes have a small plastic fuse puller tool clipped inside.
- Visually inspect the fuse. Look at the metal wire inside the plastic housing. If it's broken or melted, the fuse is blown.
- Use a multimeter (for a definitive test). Set your multimeter to the continuity setting (it often looks like a sound wave symbol). Touch one probe to each metal blade on the fuse. If the multimeter beeps, the fuse is good. If it remains silent, the fuse is blown.
When replacing a fuse, always use a new one with the exact same amperage (Amp) rating. Using a higher-rated fuse can cause severe damage to the electrical system and create a fire hazard.
Common Blown Fuses on the 2020 GMC Sierra 1500
-
Cigar Lighter / 12V Power Outlet Fuse (F18, F19 - Instrument Panel): This is one of the most common fuses to blow. It often happens when a faulty phone charger or another plugged-in device shorts out. Before replacing the fuse, unplug all devices from the outlets.
-
Fuel Pump Fuse (F12 - Engine Compartment): If your Sierra cranks but won't start, the fuel pump fuse could be the culprit. A failing fuel pump can draw too much current and blow the fuse as a protective measure. If the new fuse blows immediately, you likely have a wiring short or a bad fuel pump that needs to be diagnosed.
-
Trailer Brake Fuse (F24 - Engine Compartment): If you frequently tow, issues with your trailer's wiring are a common cause for this fuse to blow. A short in the trailer's lighting or brake wiring can overload the circuit. Check the trailer wiring harness and the 7-pin connector for corrosion or damage before replacing the fuse.
-
Blower Motor Fuse (F2 - Engine Compartment): If your truck's heat and A/C fan suddenly stops working on all speeds, this fuse is the first thing to check. If the fuse is blown, the blower motor itself may be failing and drawing excess current, or an object may be jamming the fan. If the new fuse blows quickly, the blower motor or blower motor resistor likely needs replacement.
If a fuse blows repeatedly, it signifies an underlying problem in that circuit that needs to be addressed. Don't simply keep replacing the fuse.
Find a trusted shop on Repairius.
Before you pull a fuse on the 2020 GMC Sierra 1500
- 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 2020 GMC Sierra 1500
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
Maintenance & repair guides
2020 GMC Sierra 1500 Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
Browse by make
Running an auto or diesel repair shop?
Compare Repairius to the shop software you're paying for
$99.99/month (first location included), unlimited users, 14-day free trial.