Repair Fuses: 2021 GMC Sierra HD Fuse Diagrams and Relay
To repair and fix the 2021 GMC Sierra HD’s electrical systems, you need to know how the fuse diagrams and relay configurations work. Fuses and relays are very important for protecting the car’s electrical connections and making sure that systems like the lights, power windows, and climate control work properly. By looking at the fuse diagrams and relay layouts that are specific to the Sierra HD, drivers and techs can quickly find and fix electrical problems. If necessary, they can replace faulty fuses or relays to get the car working again and stop more damage from happening. By using detailed and easy-to-understand diagrams, people can easily figure out how to fix things by navigating the fuse and relay configurations. This keeps the vehicle’s electrical systems reliable and running well.
2023 GMC SIERRA 1500 Specs, Price, Features, and Mileage (Brochure)
Electrical System
Electrical System Overload
The vehicle has fuses to protect against anelectrical system overload. Fuses also protect power devices in the vehicle. Replace a bad fuse with a new one of the identical size and rating. If there is a problem on the road and a fuse needs to be replaced, there are some spare fuses and a fuse puller in the left instrument panel fuse block. The same amperage fuse can also be borrowed. Choose some feature of the vehicle that is not needed to use and replace it as soon as possible.
Headlamp Wiring
An electrical overload may cause the lamps to go on and off, or in some cases to remain off. Have the headlamp wiring checked right away if the lamps go on and off or remain off.
Windshield Wipers
If the wiper motor overheats due to heavy snow or ice, the windshield wipers will stop until the motor cools and will then restart. Although the circuit is protected from electrical overload, overload due to heavy snow or ice may cause wiper linkage damage. Always clear ice and heavy snow from the windshield before using the windshield wipers. If the overload is caused by an electrical problem and not snow or ice, be sure to get it fixed.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are protected from short circuits by a combination of fuses and circuit breakers. This greatly reduces the chance of damage caused by electrical problems.
Danger
Fuses and circuit breakers are marked with their ampere rating. Do not exceed the specified amperage rating when replacing fuses and circuit breakers. The use of an oversized fuse or circuit breaker can result in a vehicle fire. You and others could be seriously injured or killed.
Warning
Installation or use of fuses that do not meet GM’s original fuse specifications is dangerous. The fuses could fail, and the result in a fire. You or others could be injured or killed, and the vehicle could be damaged.
To check a fuse, look at the silver-colored band inside the fuse. If the band is broken or melted, replace the fuse. Be sure to replace a bad fuse with a new one of the identical size and rating. Fuses of the same amperage can be temporarily borrowed from another fuse location if a fuse goes out. Replace the fuse as soon as possible.
Engine Compartment Fuse Block
If the vehicle has a diesel engine, see the Duramax diesel supplement. The engine compartment fuse block is in the engine compartment, on the passenger side of the vehicle.
Lift the cover to access the fuse block.
Caution
Spilling liquid on any electrical component on the vehicle may damage it. Always keep the covers on any electrical component.
A fuse puller is available in the left instrument panel end cap. The vehicle may not be equipped with all of the fuses, relays, and features shown.
Instrument Panel Fuse Block (Left)
The left instrument panel fuse block access door is on the driver-side edge of the instrument panel. The vehicle may not be equipped with all of the fuses, relays, and features shown. Pull off the cover to access the fuse block. A fuse puller is available in the left instrument panel end cap.
The vehicle may not be equipped with all of the fuses, relays, and features shown.
Instrument Panel Fuse Block (Right)
The right instrument panel fuse block access door is on the passenger side edge of the instrument panel. Pull off the cover to access the front of the fuse block.
To access the back of the fuse block:
- Push the tab at the top of fuse block down.
- Pull the top of the fuse block outward.
- Reverse Steps 1–2 to reinstall.
The vehicle may not be equipped with all of the fuses, relays, and features shown.
How to Change the Fuse of GMC Sierra HD
Certainly, here’s a detailed guide on how to change a fuse in the GMC Sierra HD:
- Locate the Fuse Box: The fuse box in the GMC Sierra HD is typically located in the engine bay or under the dashboard on the driver’s side. Use the fuse box diagram on the cover or inside the lid to identify the fuse corresponding to the malfunctioning component.
- Turn Off the Vehicle: Before beginning any work on the electrical system, turn off the ignition and ensure all accessories are switched off to prevent electrical hazards.
- Identify the Blown Fuse: Inspect the fuses visually or use a multimeter to determine which fuse has blown. A blown fuse will have a broken filament visible inside the fuse.
- Prepare Tools: Gather necessary tools, including a fuse puller or needle-nose pliers, and a replacement fuse of the same amperage rating.
- Remove the Blown Fuse: Using the fuse puller or needle-nose pliers, grasp the blown fuse firmly and pull it straight out of the fuse box. Be careful not to damage surrounding components.
- Install the Replacement Fuse: Take the replacement fuse and insert it into the empty slot in the fuse box, ensuring it is seated securely.
- Test the Component: Once the replacement fuse is installed, turn on the ignition and test the malfunctioning component to verify that it is now functioning properly.
Tips:
- Use the Correct Amperage: Always replace a blown fuse with one of the same amperage rating to prevent electrical damage or fire hazards.
- Inspect Surrounding Fuses: Check adjacent fuses for signs of damage or wear, as multiple blown fuses may indicate an underlying electrical issue.
- Check for Loose Connections: If a fuse blows repeatedly, inspect the corresponding electrical circuit for loose connections, damaged wiring, or faulty components.
- Keep Spare Fuses: It’s advisable to keep a variety of spare fuses of different amperage ratings in your vehicle for emergencies.
By following these steps and tips, you can safely and effectively change a fuse in the GMC Sierra HD, ensuring the continued functionality of your vehicle’s electrical system.
FAQs
Fuses and relays safeguard the vehicle’s electrical circuits, protecting them from overloads and ensuring the proper functioning of various systems such as lights, windows, and climate control.
If you suspect a blown fuse, use the fuse diagram to identify the corresponding fuse and replace it with one of the same amperage rating to restore functionality.
Yes, the 2021 GMC Sierra HD may use blade-type fuses or mini-blade fuses, which can be identified by their size and amperage rating markings.
Yes, fuses with transparent housing allow for visual inspection, while others may require testing with a multimeter to confirm their functionality.
Basic tools such as a fuse puller or needle-nose pliers may help remove and replace fuses and relays in the 2021 GMC Sierra HD.
Relays typically do not have a reset function; if a relay is malfunctioning, it may need to be replaced with a new one to restore proper operation.
Fuses may blow due to electrical overloads, short circuits, or faulty components in the electrical system of the 2021 GMC Sierra HD.
Regularly inspecting fuses and relays for signs of damage or wear, and addressing any electrical issues promptly, can help prevent fuse and relay problems in the 2021 GMC Sierra HD.
Before handling fuses and relays, ensure that the vehicle’s electrical system is turned off to prevent accidental shocks or damage, and always use caution when working with electrical components.
Signs of a faulty relay in the 2021 GMC Sierra HD may include non-functioning electrical components, intermittent operation, or unusual noises coming from the relay itself.
Useful Links
View Full PDF: GMC Sierra HD 2021 User Manual | Auto User Guide
2023 GMC SIERRA 1500 Specs, Price, Features, and Mileage (Brochure)