Where is the horn relay on a 2013 Toyota Tundra?
In a 2013 Toyota Tundra, the horn relay is located in the engine compartment fuse/relay box on the driver’s side, and it’s labeled on the box lid diagram as HORN. If you don’t see it there, the horn relay may also be in the interior fuse box behind the dash, but the engine bay box is the primary location.
Overview of the horn circuit
The horn system is powered through a relay that switches battery voltage to the horn when the horn switch is pressed. The relay is a safety and reliability component that can fail independently of the horn itself, so locating and testing it is often a first step in diagnosing a non-working horn.
Where to locate the horn relay
Before you begin, understand that on most Tundra models the horn relay sits in the under-hood fuse/relay box on the driver’s side of the engine compartment. The box lid contains a diagram that marks the location of the HORN RELAY. If you don’t find a label there, check the diagram on the inside of the lid for the exact position or check the interior fuse box diagram.
To help you visually identify the relay location, the following list describes the typical process:
- Park safely, turn off the engine, and open the hood. Wear eye protection if needed and avoid touching hot components.
- Locate the engine compartment fuse/relay box on the driver’s side of the engine bay (near the front-left corner or close to the strut tower).
- Remove the fuse/relay box cover and read the diagram on the underside or the inside of the lid. Look for the label “HORN” or “HORN RELAY.”
- Identify the relay in the marked position and gently pull it straight out to inspect or swap with a identical relay from the box for a quick test (for example, swap with a relay of the same size and rating that you know is good).
- Reinstall the cover and test the horn to see if it’s functioning correctly.
In some Tundra configurations, if the horn relay isn’t found in the engine compartment box, there may be a secondary fuse box inside the cabin (often behind the kick panel or under the dash). Always consult the owner’s manual or the diagram in the fuse box cover for the exact layout for your vehicle.
Testing and replacement tips
If you suspect a faulty horn relay, you can perform a basic test or replacement to confirm. The following steps help verify the relay’s function without specialized tools:
- Swap the suspected horn relay with another identical relay in the same box (e.g., a relay with the same pin count and amperage) to see if the horn starts working.
- Inspect the relay and wiring for signs of corrosion, burning, or loose connections. Clean or reseat connectors as needed.
- Check the horn fuse in the same box; a blown fuse can mimic a relay failure. Replace if necessary and retest the horn.
- If the horn still does not operate after swapping the relay and checking fuses, test the horn itself by bypassing the relay with a direct power connection (careful handling, and only as a diagnostic step) or consult a technician for further diagnosis.
Note: Always disconnect the negative battery terminal before handling electrical components to prevent short circuits or shocks. Use the correct replacement relay matching the vehicle’s original specification (typically a 5-pin 12V automotive relay).
Summary
The horn relay on a 2013 Toyota Tundra is primarily located in the engine compartment fuse/relay box on the driver’s side, labeled HORN on the lid diagram. If you can’t find it there, check the interior fuse box diagrams in the dash area. Use caution when working with electrical components, and consider swapping relays with a known-good unit to confirm a relay fault before replacing other components.
For persistent horn issues, refer to the vehicle’s service manual or contact a qualified technician to ensure proper diagnosis and safe repair.
