User Manual

Product: Single trumpet MotoHorn™ with 12V compressor

Fitment: Motorcycles, cars, trucks, boats, and other vehicles with 12V power supply

Package Includes: Single trumpet MotoHorn™, 12V air compressor, air line, bag of fixings, user manual

Working voltage: 12V

Working current: 20A
MotoHorn User Manual

Before the installation

  1. Please install MotoHorn™ following these instructions.
  2. Power off your motorcycle before installing MotoHorn™.
  3. In order to minimize voltage loss, make wires as short as you can.
  4. IMPORTANT! To get the loudest results, please use wiring that can support 15-20A of current. We recommend using 12 American Wire Gauge (AWG) thick wire as main power for each compressor.
  5. In order to reduce airflow related problems, we recommend making the air line as short as you can.
  6. Make sure the air line has free air flow and isn’t blocked by hard bends.
  7. Keep the compressor away from direct contact with engine and other motorcycle components that produce a lot of heat.
  8. TIP: Install MotoHorn™ under the stock horn button and run them both simultaneously for best multi-tone effects.

How to install, basics

  1. Bolt the air compressor and horn to the desired mounting spot. Suggestion: Install horn trumpet slightly downwards — this prevents water accumulating in it.
  2. Do the wiring. There are 2 ways to do the electrical wiring, explained below.
  3. Connect the air compressor and horn by using the provided air line. Air line is replaceable (inner diameter: 0.275″).
  4. Enjoy your loud upgraded MotoHorn™.

How to wire your MotoHorn™

Wiring your MotoHorn™ is easy and requires following just 5 steps. We recommend using the relay method explained below to get the loudest results.

Relay is basically a magnetic switch that is installed on new 12 gauge main wiring, it allows you to use thin stock wiring to control as many MotoHorns™ as you like.

MotoHorn™ User Manual Wiring Diagram

Recommended parts: 12 gauge wire, 20-40A 4 or 5 pin relay, 20-40A inline fuse, and some crimp terminal connectors so that you can easily plug it to the compressor/relay pins. You can get all of these from any automotive store.


Using a 20-40A 4 or 5 pin relay. This connection uses relay to engage the main 12 gauge wiring.

Relay pins are universal and have the same number markings. If you are using a 5 pin relay, pin number 87a can be left blank:

  1. Use 12 AWG wire: Wire power from battery “+” to pin number 30. Also install 20-40A fuse closer to the battery on this same wire for safety reasons.
  2. Use 12 AWG wire: Wire air compressor “+” to relay pin number 87.
  3. Use 12 AWG wire: Wire air compressor “-” to ground from motorcycle frame. You can also wire it to the battery “-”.

Your main 12 AWG wiring is now done. Now your relay needs to be activated by the stock horn wire or by a new switch. You can use any wire size:


  1. Find your stock horn positive wire or your stock horn button positive wire. Connect it to pin 86.

    TIP: Keep your stock horn in the system and run them both simultaneously, this way you get the best multi-tone effect.

    Common mistake happens here: When taking positive from your stock horn button, make sure you take it from the side that isn’t constantly under the positive current. Otherwise your horn and relay would be always on.

  2. Ground your relay pin 85 to the motorcycle frame or wire it to the battery “-”.

    Your MotoHorn™ can now be activated via the stock horn button. Installation complete.

For new switch:

  1. Use any wire size: Wire power from the other side of the switch to relay pin number 86.
  2. Use any wire size: Your switch needs a positive power source. You can take this from the battery “+” or from somewhere from the dash wiring. If you wire it from the battery, install a 5-15A fuse closer to the battery for safety reasons.

    Your MotoHorn™ can now be activated via a new horn button. Installation complete.

Here is a link to a YouTube video that explains relay and connections to it really well, this video is not ours:

Connecting 2+ MotoHorns™

Installing multiple MotoHorns™ is easy. For main wiring, wire each horn separately with their own 12 AWG wire and a relay. To control all of these horns under the same button, connect every relay’s pin 86 to the same stock horn or new button wire.

Common mistake happens here: Don’t split the 12 gauge wire between the compressors. Each compressor needs its own 12 gauge wire for 20A of current. If you are installing 2 horns, then you should have 2 separate 12 gauge wires coming from the battery “+”.


  1. Do not let water get directly into the horn while washing your motorcycle. If it did, do not use your horn and let it dry out. Suggestion: when installing the horn, tilt it downwards to prevent this from happening.
  2. To extend MotoHorn™ compressor life, don’t honk frequently for a very long period of time.
  3. Remember: professional work is always better and safer than doing it on your own, if there is anything wrong with it, we recommend using professional service.

Common problems and maintaining your horn:

Problem description: MotoHorn™ works only once and you have to restart the motorcycle for it to work again.

Solution: Your wiring is too thin for 20A of current, please follow the relay and 12 AWG wire installation method.

Problem description: Horn not working at all/very weak sound.

Solution: Test out the compressor straight on a battery with some 12 gauge wire. If the compressor works, then the problem is either the wiring or the air line has been blocked.

Problem description: After a very long-term use, grease may clog up in the air compressor and it starts blocking the air flow. Your MotoHorn™ sound is then compromised.

Solution: Pour machine oil into the air compressor through the air tube, then honk the horn until all grease gets blown out from the compressor.

Dual Track MotoHorn