2021 GMC Yukon Fuse Box Diagram & Amperage

Quick Answer

The 2021 GMC Yukon features three main fuse box locations: under the hood, under the instrument panel (on the passenger side kick panel), and in the rear cargo area.

Under-Hood Fuse Box

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

Relay Locations (Under-Hood):

• RL1: Fuel Pump Relay
• RL2: Starter Relay
• RL3: Headlight Low Beam Relay
• RL4: Headlight High Beam Relay
• RL5: Horn Relay
• RL6: Blower Motor Relay
• RL7: A/C Compressor Clutch Relay
• RL8: ECM/PCM Main Relay

Instrument Panel Fuse Box (Passenger Side)

This fuse box is located on the passenger side of the instrument panel, behind a removable kick panel or trim cover. It primarily houses fuses for interior electrical components, infotainment, and various cabin accessories.

Rear Cargo Area Fuse Box

Located in the rear cargo area, often behind a removable trim panel on the driver's side. This fuse box typically contains fuses for rear accessories, power liftgate, rear climate control, and trailer wiring.

How to Test a Fuse

Testing a fuse is a straightforward process that can help diagnose electrical issues. You will need a fuse puller (usually found in the fuse box lid) and a multimeter.

1. Locate the suspected fuse: Refer to the fuse box diagrams above and the legend on the fuse box cover to identify the fuse for the circuit that is not working.
2. Turn off the ignition and disconnect the battery (recommended): While not always strictly necessary for basic testing, it's good practice to prevent accidental shorts or surges, especially when working with critical circuits.
3. Remove the fuse: Use the fuse puller to carefully remove the fuse from its slot.
4. Visually inspect the fuse: A blown fuse will often have a visible break in the metal wire connecting the two prongs. However, sometimes the break is not obvious.
5. Test with a multimeter:
   • Set your multimeter to the continuity setting (usually signified by an audible beep or a diode symbol).
   • Touch one probe of the multimeter to each metal prong of the fuse.
   • If the fuse is good, the multimeter will beep or show a reading close to zero ohms (indicating continuity). If the fuse is blown, the multimeter will show no continuity or an "OL" (open loop) reading.
6. Replace if necessary: If the fuse is blown, replace it with a new fuse of the exact same amperage and type. Never substitute a higher-amp fuse, 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 constant use or the components they protect. On the 2021 GMC Yukon, common culprits often include:

• Cigar Lighter / 12V Power Outlets (Instrument Panel Fuse Box, F2/F3): These frequently blow due to overloads from charging multiple devices or using high-power accessories. Check for faulty chargers or accessories first.
• Blower Motor (Under-Hood Fuse Box, F5): A struggling or seized blower motor can draw excessive current and blow its fuse. If the fuse blows repeatedly, the blower motor itself or its resistor may need replacement.
• Trailer Brake Controller (Under-Hood F12 / Rear Cargo F12): Issues with trailer wiring or a short in the trailer system can cause these fuses to blow. Always inspect your trailer wiring before connecting.
• Radio / Infotainment (Instrument Panel Fuse Box, F1): While less common, issues with aftermarket installations or internal component failures can sometimes lead to this fuse blowing. If your radio is completely dead, check this fuse.
• Headlights (Under-Hood Fuse Box, F6-F9): A failed headlight bulb can sometimes cause its associated fuse to blow. If only one headlight is out, check the bulb first, then the fuse.

Always remember to consult your vehicle's owner's manual for the most accurate and detailed fuse box information, as fuse assignments can sometimes vary slightly between trim levels or production batches.

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