Why might a car horn not work?

If a car horn is not working properly, its fuse, siren or button may be damaged. Before the horn can be fixed, the vehicle will need to be diagnosed properly.

The horn system on a standard car utilizes a relay under the dash of the vehicle, along with a switch and siren. When the switch is pressed, power flows through the relay and makes the horn work. If any one of these components is damaged, the horn will fail. Use the following steps to help diagnose a horn problem.

1. Locate the fuse

The horn fuse is found inside the engine compartment fuse box.

2. Probe the fuse

Use a test light to see if the fuse has power, and replace if necessary.

3. Check the horn circuit

Use a test light to probe the horn circuit.

4. Repair the circuit

Replace the damaged wire, siren, relay or switch if necessary.