Get To Know Your Horn Kit

Get To Know Your Horn Kit!

For anyone that is new to aftermarket horns, learning how your horn kit works can be intimidating. There are many different parts that you may have never heard of, but it is good to get familiar with how a horn kit works, whether you still need to decide what to get or if you already have a kit and are just looking to know how to maintain your system and troubleshoot any issues that may come up. Today we will cover the main components of a train horn kit, what they do, as well as how to get the most out of your system.

Main Components: Horn, Air Compressor, and Air Tank

While there are many different working parts within a horn system, there are three main components that play an integral role in making sure you are heard on the road. What kind of horn, air compressor, and air tank you have will affect not only what your kit sounds like, but also different capabilities of your onboard air system. Knowing what each component does and how it affects other components is important for deciding what to purchase as well as making sure the kit you have keeps working great for years.

The Horn:  The whole reason for the kit. We probably don’t need to tell you what a horn does, but getting familiar with how it works and what makes the horns sound different from each other will help you in choosing the right horn as well as make sure it continues to blast loud and proud.

There are two main types of horns in our kits: train horns and air horns. Train horns are classified by their low and deep tone as well as their typically higher volume. Air horns, on the other hand, are generally higher in pitch and not quite as loud as a train horn. Air horns can still be incredibly loud and some air horns can be louder than some train horns, so it really comes down to personal preference on which one is better.

There are many factors that determine how a horn will sound, such as the shape and length of the bell, the material and components that it is made out of, as well as the amount of air pressure it is receiving. Many horns have multiple bells and are tuned to form a specific chord. Generally, the larger the horn and the more bells it has, the louder it will be. There are exceptions to that rule, such as our Shocker XL Horns that are compact but have the volume of a huge metal-cast train horn, but that mainly comes down to the components the horn is made with. That's why it is imperative to get a horn made with quality material and components.

The horns themselves are generally maintenance-free, but keeping your air system free of moisture and debris will ensure your horn maintains the intended pitch and volume. No matter what you do, your horn is going to get wet, so ensuring your horn is made with stainless steel diaphragms and draining your air tank on a regular basis will ensure that your horn sounds right every time you blast it.

The Air Compressor:  The muscle of the system. The more powerful your air compressor, the more capabilities your kit is going to have. The biggest decision other than the horns is choosing what compressor to get. Knowing how they work and how to keep them maintained is probably the most important part of understanding your kit as a whole.

The air compressor intakes air, filters it and pushes it into your air tank. Every single horn requires a compressor and the louder horns require more air and higher pressure, so it is important to have a compressor that is rated for your size tank and intended pressure.

Generally, there are two main types of air compressors: Fast-Fill and Constant or Heavy Duty. Fast-Fill compressors do exactly what it sounds like: fill your tank up fast. Fast-Fill compressors sacrifice duty cycle for speed, so usually kits with Fast-Fill compressors are best suited for people that only want to blow their horns a lot and often and want to make sure there is air in the tank ready to honk again as soon as possible.

On the other hand, Constant or Heavy-Duty compressors sacrifice speed for a longer or constant duty cycle. A compressor’s duty cycle determines how long the compressor can run continuously without having to stop to cool off. If you are going to be doing any regular pneumatic tasks, such as tire inflation or air suspension, you will want a compressor with a long or constant duty cycle.

Some compressors can be both Fast-Fill and Constant Duty. Viair’s 485 series compressor is a great example of this with a constant duty cycle up to 200 PSI and a fast fill rate.

You want to make sure that your compressor is installed upright and is kept away from moisture and debris. Some compressors are more water-resistant than others, so ensure the kit you purchase is designed to be out in the elements if you plan on installing your system on the exterior of the vehicle as there are some systems that are designed for indoor use only, such as our HornBlasters 127H Air Source Unit and 228H Air Source Unit. While our exterior systems are designed to withstand the elements, keeping your compressor as dry as possible is going to ensure the longevity of your system. If needed, the filter for the compressor can be relocated to a dry area such as a toolbox, using the Air Filter relocation kit supplied with the air compressor.

Another important part of installing your compressor is making sure you don’t over-torque your check valve. Your check valve is the small metal piece that connects your leader hose from the compressor to your air tank. Make sure your torque wrench is set to no more than 15-17 pounds of torque. Your check valve is a directional valve and if it is broken it will cause air back into your compressor, rending your air system inoperable. If you must use something other than a torque wrench to tighten, make sure you are only going a little past hand tight.

The Air Tank:  The size of your air tank determines how much air you will have to work with. Being familiar with your air tank is important in knowing that you get the right size for what you plan to do with your system as well as make sure that it is properly maintained to ensure your system last as long as your ride does.

Just as important as choosing the right compressor and horns, the size of your air tank determines what capabilities your system will have. For example, you probably aren't going to have enough air to power a set of Nathan AirChimes with a 1-gallon air tank. Having more air is always better than having less, but there are some things to consider when deciding what size tank to go with.

The biggest determining factor is how much room you have on your vehicle. We have tanks as big as 20 gallons, but it probably won't fit on your Saturn. Also, keep in mind that most compressors are only rated for up to 5 gallons, meaning you will need a compressor for every 5 gallons of air that you have. For example, our 8-Gallon kits run dual compressors.

If you only plan on using your system to honk the horns, what size air tank you need really comes down how long you want to blast your horns continuously. For most horns, each gallon of air is going to give you about 2 seconds of blast time. One of our 2-Gallon kits, for example, will give you about 4-5 seconds that you can lay on the horn continuously.

The most important way to maintain, not just the air tank, but the entire system is to drain your air tank regularly. The number one cause of issues with customer's kits is due to moisture build-up in the components from not draining the tank. Something that takes 5 minutes to do every once in a while can add years of longevity to your system and possibly save you hundreds of dollars in new parts. The drain should be installed on the bottom part of the tank where the water collects and you use it by simply turning it counter-clockwise until air and moisture start coming out. Make sure you tighten it back up before you fill the tank back up with air and that is it!

Minor Components: Pressure Switch, Solenoid Valve, Safety Blow-Off, and Air Gauge

While your air tank, air compressor, and horns make up the meat and potatoes of your kit, there are a few other parts that are just as important for your horn kit to be functional. When installing your kit, it is vital that these parts are installed correctly. Many of the issues that arise from the kits are due to these three parts either not being installed or maintained correctly, so getting yourself familiar with these smaller components is important to ensure the longevity of your kit.


The Pressure Switch:  Possibly the most important part in your entire kit, without a properly working pressure switch, your kit will not work. While there isn’t really any maintenance that needs to be done (other than draining the tank on a regular basis), wiring your pressure switch is vital to getting your system to work.

Your pressure switch is the component that is responsible for turning on and off your compressor automatically. As you can see from the picture above, pressure switches can come in a variety of shapes and sizes. Some pressure switches come with a built-in relay, while others you will have to wire to the relay yourself. What pressure switch you have will be different depending on what system you have. For example, most of our medium-sized kits will have a pressure switch with a built-in relay, where our smaller and largest kits will have the standard “Bottle-cap” pressure switch.

The most important thing to note is that some pressure switches are sealed and some are not. While all pressure switches can be on systems installed outside the vehicle, some pressure switches are more weather resistant than others. If you plan on getting your ride wet or dirty on a regular basis, you want to get a sealed pressure switch, such as one that comes with leads.

The Solenoid Valve:  Your Solenoid Valve also commonly known as the Air Valve, is the component that controls the airflow to your horns. If installed improperly your horn will not sound off. Knowing how your solenoid valve works will ensure that your horns will sound off at your command.

The Solenoid Valve works by using a magnet and plunger. When the valve receives power it will activate the magnet that pulls the plunger up allowing air to pass through. The plunger is spring-loaded so as soon as the valve stops receiving power, the magnet disengages, Causing the plunger to close immediately, stopping the airflow. Now, these valves are directional valves as well. Meaning there is an inlet and outlet which can be determined by the arrow located on the brass part of the valve. When installing confirm the arrow is in the direction of flow. Most valves have two of the same color wire due to it being dual polarity. Which means either wire can be the power or ground. Ground one wire near the valve and the other wire will go to your toggle switch/push button.

The Safety Blow-Off:  Your safety blow-off is used to relieve pressure in cases of emergency. Using a loaded spring, once the pressure reaches a certain point it will release the spring, causing the fitting to release pressure from the tank. To keep the tank from over-pressurizing.

The Safety Blow-Off valve is a fitting located on the tank in case of emergencies. When a pressure switch goes bad and continues to keep your compressor on, over pressurizing the tank could cause it to explode. The Safety Blow-Off is rated for a pressure that is a little bit higher than your Pressure Switch.For example, most of our kits run at 150 PSI and will have a 175 PSI Safety Blow-Off. A Safety Blow-Off is a must when using any air system. Making sure you have one properly installed on your tank will ensure that should one part fail, the rest of your kit will stay intact and does not become dangerous due to an over pressurized air tank.  

The Air Gauge:  Your Air Gauge is used to monitor the air pressure in the tank. Being able to monitor the tanks pressure allows for easier troubleshooting when diagnosing problems.

The Air Gauge is used to monitor the air pressure in the tank. We have two types of gauges, Digital Air Gauges and Manual Air Gauges. Most of our kits include a Manual Air Gauge, but many of our customers will also substitute it for a Digital Air Gauge so they may monitor it easily from the cab of the vehicle. While our systems are automatic and will regulate the air pressure for you, having an Air Gauge is highly important for diagnosing issues with your onboard air system. Simply having an Air Gauge installed could save you time and money by knowing exactly what issue you are having with your system instead of having to guess.

Want to Learn More?

While we cover the basics here, there is still so much more to learn about Train Horns, On-Board Air and what they are capable of, with new technology being made available constantly. You now have the tools to get the most out of your horn kit, but it doesn’t stop here! We are always available by phone, email or chat should you have any questions that we didn’t cover here. Happy Honking!