How to Add an Air Horn to a Motorcycle

As a required safety item for road-going motorcycles, the horn is designed to audibly alert other motorists of your presence. As difficult as it already is for drivers to visually detect a motorcyclist, the added security of a horn should help. Unfortunately, most motorcycle horns are barely audible and are relatively useless. Unless you have an air horn, that is. Composed of trumpets powered by an air compressor, air horns are capable of reaching attention-getting volumes at or near 125 decibels. As a bonus, they are fairly simple to install.

Things You'll Need

• Screwdriver
• Socket set
• Socket wrench
• Air horn kit
• Cable ties

Instructions

1. Park your motorcycle on a clear, level surface and turn the ignition to the "Off" position.

2. Disconnect the battery, removing the negative (-) terminal bolt first, followed by the positive (+) terminal bolt. Do not allow the wire leads to contact the frame or other metal parts.

3. Locate and remove the factory-equipped horn by unscrewing the nut on the back of the horn. Most air horns will use the factory horn mounting location.

4. Install the air horn trumpets on the original horn mounting location. Slide the threaded end of the bracket into the mounting hole, followed by the lock washer. Tighten the nut to secure.

5. Mount the air compressor to the right front fork or lower triple tree with cable ties, facing the compressor outlet upwards. Route the air hose from the trumpets to the compressor, running from the left front fork and behind the headlight to the compressor.

6. Place the compressor relay near the battery, connecting the ground wire to the frame. The positive (+) wire will connect to the battery's positive (+) terminal. Route the positive (+) wire and two black wires from the relay to the compressor, following existing wiring as mush as possible. Connect the black wires to the original horn wiring and the positive (+) wire to the compressor. Connect the negative (-) terminal on the compressor to a solid ground location on the frame.

7. Secure the air horn's wiring to the motorcycle's existing wiring harness with cable ties. Attach the fused wire from the relay and the motorcycle's positive (+) wire lead to the battery, followed by the negative (-) wire lead.

Tips & Warnings

• Refer to a service manual specific to your motorcycle for horn removal details.

• Take your time and do the job right.

• If you do not feel comfortable working with your motorcycle's electrical system, have the work done by a qualified technician.

• When disconnecting the battery, do not let the terminals contact the frame, preventing grounding and electrical shock.

References

• "The Professional Motorcycle Repair Program;" Professional Career Development Institute; 1995

Resources

• Air horns; BJ Specialties.com