2021 Toyota Corolla Fuse Box Diagram & Amperage Guide

Quick answer

The 2021 Toyota Corolla features three main fuse box locations: under the hood (engine compartment), behind the glove compartment (passenger side dash), and in the trunk (cargo area).

Under-Hood Fuse Box (Engine Compartment)

This fuse box, located in the engine bay, typically near the battery, houses fuses and relays for critical engine functions, lights, and other high-current systems.

Relays located in the Under-Hood Fuse Box often include:

• EFI Main Relay: Powers the ECM/PCM and fuel injection system.
• IGNition Relay: Controls power to the ignition system.
• Starter Relay: Engages the starter motor.
• H-LP Low Beam Relay: Controls power to the low beam headlights.
• H-LP High Beam Relay: Controls power to the high beam headlights.
• Radiator Fan Relay: Activates the radiator cooling fan.
• A/C Clutch Relay: Engages the A/C compressor clutch.
• Horn Relay: Activates the horn.

Important Note: The exact layout and labeling of fuses and relays may vary slightly depending on your Corolla's specific trim level and options. Always refer to the fuse diagram printed on the inside of your fuse box cover for the most accurate information for your vehicle.

Passenger Compartment Fuse Box (Behind Glove Compartment)

This fuse box is typically located on the passenger side, behind the glove compartment or kick panel. It protects electrical components within the cabin, such as the radio, power outlets, and accessory systems.

Relays in the Passenger Compartment Fuse Box:

• While fewer relays are typically found here compared to the under-hood box, you might find relays for specific accessories or the blower motor.

Trunk/Cargo Area Fuse Box

Some 2021 Toyota Corolla models, especially those with premium audio systems or specific accessory packages, may include a fuse box in the trunk or cargo area. Its purpose is often to protect dedicated circuits for these systems.

Relays in the Trunk/Cargo Area Fuse Box:

• Relays in this location are rare and typically limited to very specific, high-power accessories like a power liftgate or advanced sound system amplifiers.

How to Test a Fuse

1. Safety First: Ensure the vehicle's ignition is off and the parking brake is engaged before working with fuses.
2. Locate the Fuse: Refer to your vehicle's fuse diagram (usually on the fuse box lid or in the owner's manual) to identify the correct fuse for the circuit you're troubleshooting.
3. Visual Inspection: Most modern fuses have a clear plastic body. Look for a broken or burnt wire inside. If it's broken, the fuse is blown and needs replacement.
4. Using a Fuse Puller: Use the plastic fuse puller tool (often found in the fuse box lid) to safely remove the fuse.
5. Test with a Multimeter (Optional but Recommended):
   • Set your multimeter to the continuity setting (looks like a speaker icon).
   • Touch the probes to the two metal prongs on top of the fuse. If you hear a beep, the fuse is good. If there's no beep, the fuse is blown.
   • Alternatively, set the multimeter to read ohms. A good fuse will show very low resistance (close to 0 ohms). A blown fuse will show an open circuit (OL or infinite resistance).
6. Replace with Correct Amperage: ALWAYS replace a blown fuse with a new one of the exact same amperage rating and physical size. Using a fuse with a higher amperage can cause severe electrical damage or even a fire.

Common Blown Fuses on This Vehicle

On a 2021 Toyota Corolla, some fuses are more prone to blowing due to common usage or potential issues. Here's what to check first for various problems:

• Cigar Lighter / 12V Power Outlets (CIG, PWR OUTLET): These are frequently blown by plugging in faulty accessories or devices that draw too much current. If your phone charger or dash cam suddenly stops working, check these fuses first.
• Radio / Infotainment System (RADIO NO.1, RADIO NO.2): Issues with aftermarket installations, short circuits in wiring, or a faulty component in the head unit can cause these to blow. If your radio or display goes blank, start here.
• Blower Motor (BLOWER): A failing blower motor, a clogged cabin air filter causing the motor to overwork, or even a short in the wiring can blow this fuse. If your HVAC fan isn't working on any speed, this is a prime suspect.
• Headlights / Tail Lights (HEAD LH/RH LO/HI, TAIL): While less common, a short in the wiring or a faulty bulb (especially if it shorts internally) can blow these. If one or more lights are out and replacing the bulb doesn't fix it, check the fuse.
• Wipers (WIPER, WASHER): Frozen wiper blades or a failing wiper motor can put excessive strain on the circuit, leading to a blown fuse. If your wipers stop working, especially in snowy or icy conditions, check the WIPER fuse.

Before replacing any fuse, try to identify and rectify the underlying cause of the blown fuse. If a fuse blows repeatedly, there's a deeper electrical issue that needs professional diagnosis.

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