2020 Toyota Tundra – Fuse Box Diagram & Amperage

Quick Answer

The 2020 Toyota Tundra features multiple fuse box locations to protect its electrical systems. You'll find fuse boxes under the hood, behind the driver's side kick panel (instrument panel), and in the cargo area/trunk.

Under-Hood Fuse Box (Engine Room R/B No. 1)

This fuse box is located in the engine compartment, typically near the battery on the driver's side. It houses fuses and relays for critical engine functions, lighting, and other high-current circuits. Always consult the lid of your specific fuse box, as configurations can vary slightly by trim level.

Relay Locations (Under-Hood):

• EFI Main Relay: Powers the EFI system, including the fuel pump relay.
• Fuel Pump Relay: Controls power to the fuel pump.
• Starter Relay: Controls power to the starter motor.
• Headlight Relays (HI/LO RH/LH): Control power to the high and low beam headlights.
• A/C Mag Clutch Relay: Controls power to the A/C compressor clutch.
• Horn Relay: Controls power to the horn.
• Radiator Fan Relay: Controls power to the radiator cooling fan.

Instrument Panel Fuse Box (Driver's Side Kick Panel)

This fuse box is located behind the kick panel on the driver's side, typically to the left of the footwell. It protects various interior electrical components, accessories, and some body control systems.

Cargo Area/Trunk Fuse Box (Power Outlet No. 3)

Your 2020 Tundra may have a smaller fuse box in the rear cargo area or under the rear seats, specifically for the rear power outlet in the bed or rear cabin. This will typically be a single fuse for that outlet.

How to Test a Fuse

Testing a fuse is a straightforward process that can save you time and money. Always turn off the ignition and any affected circuits before testing or replacing fuses.

1. Locate the Fuse Box: Refer to your owner's manual or the quick answer section above to find the correct fuse box.
2. Identify the Suspect Fuse: Use the fuse diagram on the lid of the fuse box (or the tables above) to identify the fuse associated with the malfunctioning component.
3. Visual Inspection: Many fuses have a visible wire inside. If this wire is broken or melted, the fuse is blown and needs replacement.
4. Use a Fuse Tester or Multimeter: For a more reliable test, use a fuse tester (a small tool that lights up if the fuse is good) or a multimeter set to continuity mode. Touch the probes to the test points on top of the fuse. If there's continuity or the tester lights up, the fuse is good. If not, it's blown.
5. Remove and Replace: Carefully pull out the blown fuse using a fuse puller (usually found in the fuse box lid or with spare fuses). Replace it with a new fuse of the exact same amperage rating and type. Never use a fuse with a higher amperage, as this can cause severe electrical damage or fire.

Common Blown Fuses on This Vehicle

While any fuse can blow, some are more commonly encountered due to their circuits' usage or design. On a 2020 Toyota Tundra, you might frequently encounter issues with:

• Cigarette Lighter / 12V Outlets (CIG, PWR OUTLET): These fuses often blow due to overloading from charging multiple devices or using high-power accessories. If your phone charger or other accessories aren't working, check these first.
• Radio / Infotainment (RADIO, ACC): Issues with audio, touch screen, or navigation can often be traced back to these fuses. An aftermarket installation or a short can sometimes lead to these blowing.
• Blower Motor (HEATER): If your HVAC fan isn't working, this large green fuse under the hood is a common culprit, especially if the blower motor has been straining or is failing.
• Trailer Circuits (TOWING series, TOWING BRAKE): If you frequently tow, the trailer-related fuses can blow due to issues with the trailer's wiring or an overload. Always inspect trailer wiring if these fuses repeatedly blow.
• Headlights / Tail Lights (HEAD, HI, TAIL): While less common, a short in a bulb or wiring can cause these to blow. If only one light is out, check the bulb first.

What to Check First:

Before replacing any fuse, try to determine what caused it to blow. Is a specific accessory drawing too much power? Is there a visible short or damaged wire? Simply replacing a fuse without addressing the underlying cause will likely result in it blowing again. If a fuse for a critical system (like EFI or ABS) blows repeatedly, it's best to consult a professional.

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