Where is the horn relay on a 2014 Toyota Tundra?
On a 2014 Toyota Tundra, the horn relay is located in the engine compartment fuse/relay box on the driver’s side of the engine bay. The diagram on the box cover will label the component as "HORN" or "HORN RELAY."
Locating the horn relay
This guide will walk you through the most common spots to find the horn relay and how to verify you’ve got the right part before testing or swapping it.
- Engine compartment fuse/relay box: The primary relay box in the engine bay on the driver’s side near the firewall usually holds the horn relay. Open the box and look for a label that says “HORN” or “HORN RELAY.”
- Interior fuse box (possible in some trims): Some configurations route the horn relay to the interior junction block under the driver’s dash. Check the diagram on the fuse box cover or in the owner's manual for “HORN RELAY.”
- Connector count and size: The horn relay is typically a standard 5‑pin automotive relay; confirm the relay has the same pin count as the one you’re replacing and that it’s the same amperage rating as the horn circuit.
If you can’t locate the relay in either box, consult the vehicle’s owner's manual or a dealership service manual for the exact fuse/relay map for your specific build date and market region.
Testing and replacement options
When the horn isn’t sounding, testing the relay or swapping it with a known-good one is a common first step. The following steps cover safe testing and replacement considerations.
- Disconnect the negative battery cable before removing or swapping relays to avoid short circuits.
- Identify an identical relay (same number of pins and current rating) from the same fuse/relay block or a spare from a known-good circuit, and swap it with the horn relay temporarily to test.
- Test the horn circuit with a multimeter: verify that power reaches the relay coil input pins (often terminals 85/86) when the horn switch is pressed, and that the relay output (terminals 30/87) supplies voltage to the horn when energized.
- Inspect the horn itself and its ground connection: a bad ground or damaged horn can also mimic a failed relay, so check the wiring to the horn assembly near the bumper.
- Check related fuses: ensure the horn fuse in the fuse box is intact and not blown, as a fuse issue can prevent operation even with a good relay.
If swapping and basic testing don’t restore function, the issue may lie in the horn switch, wiring harness, or the horn itself, and professional diagnosis may be needed.
Safety note
Working around the battery and relays can present a risk of shock or short circuits. If you’re unsure, consult a qualified mechanic or use proper safety gear and procedures.
Summary
For a 2014 Toyota Tundra, the horn relay is typically located in the engine compartment fuse/relay box on the driver’s side of the engine bay, with the diagram on the cover indicating the exact position. If you can’t find it there, check the interior fuse box and confirm with the owner’s manual. Testing involves swapping with a known-good relay and inspecting the horn, ground, and related fuses. When in doubt, professional service can ensure the horn system is diagnosed correctly.
