Kia Sorento Third Generation (2015-2020) Horn Not Working: Troubleshooting Guide

Symptoms

• Horn does not sound when pressed.
• No clicking noise from the relay when the horn button is pressed.
• Dashboard horn warning light (if equipped) may or may not illuminate.

Diagnostic Steps

Step 1: Check the Horn Fuse

• Tools Required: Fuse puller or needle-nose pliers, multimeter.
• Procedure:
  1. Open the driver’s side door and remove the fuse panel cover located under the dashboard.
  2. Locate the horn fuse (refer to the owner’s manual for specific fuse location).
  3. Use the fuse puller or needle-nose pliers to extract the fuse.
  4. Inspect the fuse visually for any signs of a blown element or use a multimeter to check continuity.
  5. If the fuse is blown, replace it with one of the same amperage (usually 15A for the horn circuit).

Step 2: Check the Horn Relay

• Tools Required: Multimeter or test light, flathead screwdriver.
• Procedure:
  1. Locate the horn relay in the engine compartment fuse box (refer to the owner’s manual for its exact location).
  2. Remove the relay by pulling it straight out.
  3. Swap the horn relay with another relay of the same type (e.g., the A/C relay) to test functionality.
  4. If the horn works with the swapped relay, replace the faulty relay with a new one.
  5. If the horn still does not work, proceed to the next step.

Step 3: Test the Horn Itself

• Tools Required: Multimeter, jumper wires.
• Procedure:
  1. Disconnect the horn wiring harness from the horn located in the front of the vehicle behind the grille.
  2. Using a multimeter, check for voltage at the horn connector while pressing the horn button.
     • Set the multimeter to DC voltage mode.
     • Connect the black lead to ground and the red lead to the horn terminal.
  3. If voltage is present (12V), the horn is likely faulty.
  4. If there is no voltage, proceed to check the horn switch.

Step 4: Check the Horn Switch

• Tools Required: Multimeter, flathead screwdriver, wire diagrams (if available).
• Procedure:
  1. Remove the steering wheel airbag (ensure to disconnect the battery first to prevent airbag deployment).
     • Use a flathead screwdriver to release the clips securing the airbag.
     • Carefully lift the airbag away and disconnect the wiring harness.
  2. Locate the horn switch on the steering wheel.
  3. Using the multimeter, check for continuity across the horn switch terminals while pressing the horn button.
  4. If there is no continuity, replace the horn switch assembly.

Step 5: Inspect Wiring and Ground Connections

• Tools Required: Multimeter, wiring diagrams, electrical tape.
• Procedure:
  1. Inspect the wiring harness for any signs of wear, fraying, or damage between the horn and the relay.
  2. Check for a good ground connection on the horn. Use the multimeter to check for continuity to ground.
  3. If the ground is poor, clean or repair the ground connection.
  4. Reconnect all wiring and components once repairs are made.

Repair Instructions

Replacing the Horn

1. If the horn is found to be faulty, purchase a replacement horn compatible with the Kia Sorento.
2. Disconnect the battery before proceeding.
3. Disconnect the old horn from its wiring harness.
4. Remove the mounting bolt(s) securing the horn and take out the old horn.
5. Install the new horn in the same location and secure it with the mounting bolt(s).
6. Reconnect the wiring harness to the new horn.
7. Reconnect the battery.

Replacing the Horn Relay

1. If the relay is faulty, remove it from the fuse box.
2. Insert the new relay into the same slot.
3. Ensure it is seated properly.

Replacing the Horn Switch

1. If the horn switch is faulty, carefully remove it from the steering wheel.
2. Install the new horn switch by following the reverse procedure.
3. Reconnect the airbag after ensuring all connections are secure.

Final Steps

1. After completing the repairs, reconnect the battery.
2. Test the horn by pressing the horn button.
3. If the horn works, reassemble any panels or covers removed during the repair process.
4. Dispose of any faulty components responsibly.

By following this structured troubleshooting and repair guide, you should be able to diagnose and fix the horn issue in your Kia Sorento effectively.