How to Wire a Car Disc Horn

Automotive horns are important safety devices used to alert distracted pedestrians and other motorists of an impending danger. Disc-type automotive horns feature a compact circular shape and a reverberating diaphragm, designed to oscillate at a predetermined audio frequency. Replacing your vehicle's defective or poor performing disc horn promotes safety and restores proper functionality. Wiring your new disc horn is an easy task when using the correct tools and accessories.

Instructions

Open the vehicle's hood and allow the engine to cool. Do not attempt to work near the engine compartment or cooling system while hot, as personal injury can occur.

Examine the areas behind the front grill and bumper area of the vehicle. Locate the original horn you wish to replace; certain vehicles may feature two horns for added safety. Refer to your vehicle's automotive repair manual for the exact location of each horn.

Remove the necessary vehicle components needed to gain access to the original horn, according to the removal procedures outlined in the vehicle repair manual.

Compare the electrical connectors used for the original horn and the new replacement. Certain factory horns may require the use a proprietary wiring connector, while after-market universal replacement horns may feature two standard male spade terminals for the + positive and - negative wiring connections.

Disconnect the wiring connections from the original horn.

Remove the bolts or screws that secure the original horn's mounting bracket to the vehicle. Remove the original horn from the vehicle.

Mount the replacement horn to the original mounting area on the vehicle, using the original screws, or the screws supplied with the new horn. Connect the wiring plug to the new horn if the component is a direct replacement that uses a proprietary terminal connection. Refer to the next steps if you are installing a universal-type disc horn.

Cut off the plug connected to the horn wiring harness. Strip off 3/8-inch of insulation from both wires. Examine the repair manual and locate the wiring schematic for the vehicle's horn circuit. Determine the correct color codes for the + positive and - negative wiring for the horn circuit.

Crimp female spade terminals to the positive and negative horn wires.

Connect the positive wire to the + horn terminal. Connect the negative wire to the - terminal on the horn.

Test the horn operation and replace the previously removed vehicle components to finish the installation process.