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

Before installation:
  1. Please install MotoHorn™ following these instructions.
  2. Power off your vehicle before the installation.
  3. (Optional) Disconnect old horn wires before the installation.
  4. In order to minimize voltage loss, make wires as short as you can.
  5. 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.
  6. In order to reduce airflow related problems, we suggest making the air line as short as you can.
  7. Make sure air line has free air flow and isn’t blocked by hard bends.
  8. Keep air compressor away from direct contact with engine and other vehicle components that produce a lot of heat.
  9. 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 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 air compressor and horn by using provided air line. Air line is replaceable (inner diameter: 0.275″).
  4. Enjoy your loud upgraded MotoHorn™.

Single MotoHorn™ METHOD 1 of the connection (basic switch install):

This circuit requires straight power from the battery and a separate switch/button that can handle 15-20 amps of current. Don't use stock wiring.

VERSION 1 wiring

Shopping list: 12 gauge wire, 20-40A inline fuse, 20A switch/button. You can get all of these from any automotive store.

Your MotoHorn™ would be inefficient if you use thin wiring and low voltage power from other accessories. We suggest using 12 gauge wiring.

  1. Wire power from battery “+” to your new switch/button. Also install a 20-40A fuse closer to battery on this wire for safety reasons.
  2. Wire power from the other side of the switch to air compressor “+”.
  3. Connect air compressor “-” to the negative from vehicle chassis/body. You can also wire it to the battery “-”.

Attention to pay to when using this method: Your switch/button needs to support ~20A of current due to being directly connected to 12 gauge wire. If you want to use thin wires with your switch or if you want to use stock horn button as the switch, then follow METHOD 2.


Single MotoHorn™ METHOD 2 of the connection (stock horn button or new switch):

This connection uses relay to engage the main 12 gauge wiring. Relay is basically a magnetic switch that is installed on main wiring, relay can be activated via your stock horn button or via a new button. This way your horn operates at full power while using thin stock wires or new low (any) amperage switch.

VERSION 2 of wiring

Stock horn button shopping list: 12 gauge wire, 20-40A 4 or 5 pin relay, 20-40A inline fuse. You can get all of these from any automotive store.

New horn button shopping list: 12 gauge wire, 20-40A 4 or 5 pin relay, 20-40A inline fuse, any switch/button, 18 gauge or smaller wire for the switch, 5-10A inline fuse (optional) for the new switch wiring. 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:

  1. Use 12 gauge wire: Wire power from battery “+” to pin number 30. Also install a 20-40A fuse closer to the battery on this wire for safety reasons.
  2. Use 12 gauge wire: Wire negative from vehicle chassis/body to pin number 85. You can also wire it from the battery “-”.
  3. Use 12 gauge wire: Connect air compressor “+” to relay pin number 87.
  4. Use 12 gauge wire: Connect air compressor “-” to ground from vehicle chassis/body. You can also wire it to the battery “-”.
  5. If you used 5 pin relay, the 5th pin (87a) can be left blank.

Your relay is now on your main wiring to compressor, now it needs to be activated by the stock wiring or by a new switch:

  1. If you want to use the existing horn button, find the horn wires and from those wires, connect the positive to relay pin 86. No additional fuse is needed here. 

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

For new switch:

  1. Use 18 gauge or thinner wire: Wire power from the other side of the switch to relay pin number 86.
  2. Use 18 gauge or thinner wire: 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 relay 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:
https://www.youtube.com/watch?v=qTZDmql8ctA


Connecting 2 MotoHorns™:

If you bought 2+ MotoHorns™ and want to bring out the multi tone better, it is very important to use thick and proper wiring. It is suggested to wire them using METHOD 2 of the connection, however you need to upgrade your main wiring to even thicker one if multiple compressors are wired under the same relay.


We recommend connecting maximum of 2 horns per relay. Easiest way to wire 2 horns would be finding a 40A+ relay that has dual 87 pins (P.S: not 87 and 87a).

  1. Use 9 or 8 gauge wire: Wire power from battery “+” to pin number 30. Also install a 40-60A fuse closer to the battery on this wire for safety reasons.
  2. Use 9 or 8 gauge wire: Wire negative from vehicle chassis/body to pin number 85. You can also wire it from battery “-”.
  3. Now use 12 gauge wire: Connect air compressor “+” to relay pin number 87. Repeat for other compressor (make sure it is dual 87 pins and not 87a on the relay).
  4. Use 12 gauge wire: Connect air compressor “-” to ground from vehicle chassis/body. Repeat for other compressor. You can also wire it to battery “-”.
If you can't find dual 87 pin relay, then you can simply do the wiring as in METHOD 2 and use 2 relays instead. Those relays can have 1 single 9 or 8 gauge wire from battery as main power (split before relays), or two separate 12 gauge wires.

Your relay is now on your main wiring to compressors, now it needs to be activated by the stock wiring or by a new switch:

  1. If you want to use existing horn button, find horn wires and from those wires, connect positive to relay pin 86. No additional fuse is needed here. If you used 2 relays, repeat for other one.

    Your relay(s) can now be activated via the stock horn button. Installation complete.


For new switch:

  1. Use 18 gauge or thinner wire: Wire power from the other side of the switch to relay pin number 86. Repeat if you used 2 relays.
  2. Use 18 gauge or thinner wire: Your switch needs a positive power source. You can take this from 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 relay(s) can now be activated via a new horn button. Installation complete.
Connecting 3 MotoHorns™:

You will need to add another relay and do the relay wiring all over, except you can activate these relays using the same switch or stock horn button. This way you can install as many horns as you want.

Enjoy your loud and upgraded horn system!

Attention!
  1. Do not let water get directly into the horn while washing your vehicle. 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 suggest using professional service.

How to maintain your horn:

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 of grease gets blown out from the compressor.

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.


GO TO MOTOHORN™ PRODUCT PAGE →