Air horn kits use an air compressor to force air through a small cone and produce an extremely high-decibel horn sound. Some states have outlawed air horn kits because they are capable of producing upward of 185 decibels. To put that into perspective, it is louder than a 12-gauge shotgun, which produces about 150 decibels.
Air horn kits are comprised of a horn system, air compressor, air hoses, electrical harness and various fittings. An air horn can be mounted almost anywhere you choose. Keep in mind, though, that if the components are exposed to extreme weather, they might fail to operate properly. You also need electrical tape and heat shrink for the connectors that provide power. These two items can help to make the air horn weather-safe and water-resistant. To install these kits, a collection of basic hand tools is necessary. A ratchet and socket set is a good idea. A power drill and drill bits are needed to mount the compressor in the bed of the truck. Zip ties or hose clamps are used to secure the horns to the underside of the vehicle. Finally, have clamps and brackets for the air hose that is used to connect the compressor and the horns. Most kits come with plenty of hose, but it's always a good idea to plan the routing of the hose before you begin.
There are several areas on a truck where the air horn can be installed. The most common place to mount the horn is directly below the engine fan. There is a wide place between the frame rails where most kits can be installed. The engine fan has a plastic shroud that protects the engine from debris. This shroud can be drilled and the support brackets placed on it to hang the horn. Another place to mount the horn is on the inside of the front bumper. There are several pre-drilled holes there that can be used to mount the horn. The compressor needs more space because it is significantly larger than the horn. The flatbed of the truck is always an option for mounting the tank. Ensure that you have enough hose to reach from the flatbed to the horn if you choose to mount it inside the flatbed. Another area that can be utilized on a truck is the frame rail. Because most trucks have a large area between the sheet metal and the sides of the frame rail, there is enough room to mount a compressor there. The bottom and sides of the frame rail are open and can be drilled, even tapped, to provide a stable mounting place for the horn. Under no circumstances should the compressor or the horn be mounted inside the cab of the truck.
