In all the states regulation says that the factory horn can produce between 100 and 110 decibel noise. The horns should be heard from at least 200 feet. But, some enthusiast truck drivers like to be heard from afar. Installing an air train horn is the best option. There comes the question of how to wire the train horn to the factory horn.
You will need to find the appropriate place to secure the horn. Depending on the size it can be mounted on the truck’s floor or in the engine compartment. Make adjustments on the dashboard to make space for the horn button. Secure the horns with bolts. Disconnect the battery and install the air compressor. Connect it to the air tank. Secure the tank. Connect the pressure switch to the tank. Connect the tank with the air valve. Connect the valve with the horn. Finally, connect the horn to the button on the dashboard.
This may sound very complicated, but we added the electrical diagram to the article. It will make this job much easier. It is very important to connect everything correctly and to not have any air leaks. Before doing this process, check the laws in your state. Some states forbid trucks from using loud air horns.
What are Train Horns and Factory Horns?
Factory horns work on a principle of a vibrating metal diaphragm. They are powered by electricity and are made of a solenoid and a thin metal disc that is made of spring steel. A solenoid is a coil of wire that forms an electromagnet.
When the solenoid receives power, it produces magnetic force, which it sends to the metal disc. This causes the disc to flex concentrically. This flexing moves apart the electrical contacts de-energizing the solenoid. When the disc returns to its original shape, the electrical contacts again close to allow power to reach the solenoid.
This process is repeated as long as the stock horn button is pressed.
The air train horns are powered with air from the compressor. Inside the horns is a plastic diaphragm that vibrates when the air goes through it. This sound is increased with the help of the bell of the horn. The air horns are louder because the whole horn and the diaphragm vibrate.
Comparison of Train Horns and Factory Horns
Their working principle is different. At the same time, the regular horns convert power to the magnetic force to flex the thin metal diaphragm. Air horns are powered by air. The air makes the plastic diaphragm vibrate, resulting in a sound signal.
Train Horn Kits and Their Components
The main components of the train horn kits are:
- The air compressor
- The air tank
- The air horns
- Brass fittings
- Wiring
- Airlines.
How to Wire Train Horn to Factory Horn
- Think about the location of all the components. There should be enough space for wiring. The power supply to the compressor should be as short as possible to maximize the efficiency
- Locate a safe spot for air horns. That can be in the space under the truck where the spare tire is located. Other options are the grill or under the hood
- Drill appropriate holes to safely secure the air horns. Secure the horns with bolts. Check every connection twice. You don’t want the horns to fall off
- Disconnect the battery power
- Find a safe space for the air compressor. Place it upright or horizontally
- Install the assembly of the compressor. Follow through on the wiring diagram. The compressor needs to be connected with the air tank, to the relay, and it needs to be grounded
- Mount the compressor where it will be exposed to airflow. Never place it upside down
- For securing all the wiring connections use Teflon tape to ensure sealing
- Mount the tank and secure it with mounting hardware. Avoid placing it near the windows or high traffic area places
- The line between the tank and the compressor needs to be long enough
- Measure the tubes and the place you want them to fit them. You need to be sure that there is enough room for everything
- Connect the air compressor to the air tank. Secure all connections with Teflon tape. Check if the connection is free of any weak spots or possible air leaks
- Connect the pressure switch to the tank. Again use Teflon sealant for connections
- Connect the air tank to the air valve. Then connect the air valve to the horn
- The fittings and connections need to be properly sealed and secured
- Make space in the dashboard for a new train horn switch. The process is similar to when connecting the glow plugs to the switch. Connect the switch with the battery and the horns
Check Out Air Horn Car Install and Relay Wiring Instructions:
Train Horn Wiring Diagrams and Their Interpretation
The red lines on the diagram are the power wires, and the black are the grounding wires. The diagram shows that you need to connect the compressor and the air tank to the relay. The relay is connected to the positive side of the battery. The switch is connected to the tubes and with the battery.
Issues When Wiring Train Horn to Factory Horn
Sometimes when you finish everything, you press the horn, and nothing happens. There could be several reasons for that.
Troubleshooting
- Check if the air tank is pressurized. If it is not, then the air horn cannot work
- Check the wiring and compare it with the diagram. Check if everything is safely connected and if all wires are in its place
- Sometimes the problem can be a blown horn fuse. Check and replace them if needed.
Legal and Safety Considerations of Wiring a Train Horn to a Factory Horn
It all depends from state to state. In some states, it is forbidden to have horns that produce very loud sounds. In others, it is not so well-defined. You can check the laws of all states, just to be sure.
FAQs
Do you need an air compressor for a train horn?
Air compressors are a necessary component of the train horn. The compressor intake air filter it and send it to the air tank. From there it goes to the horns. When choosing a compressor, you need to know what air tank size you will use. You need to have a compressor of the appropriate rate.
Can I put a different horn in my car?
Yes, you can. You need a circuit of a horn you want to use and to rewire it in place of the factory horn.
How much pressure does a train horn need?
Air horns run at a much higher pressure than regular horns. There are horns with different pressures, but 150 PSI is considered the best pressure for a horn.
Conclusion
Truck drivers love to customize and tune their drives. It is either performance boosts or transmission boosts. But there is also more exotic stuff, like installing air horns. The process demands some electrician and mechanical knowledge. If you are a DIY person, you can read a diagram and know what to do. But, if you are unsure about this department, we advise you to contact a professional.
