Customizing a Harley-Davidson motorcycle is a popular pursuit among riders who seek to enhance both the functionality and aesthetics of their bikes. Among the many accessories available, air horns are a popular addition that not only improves the bike’s presence on the road but also provides a louder and more distinctive sound compared to traditional horns. This article provides a detailed and comprehensive guide to installing air horns on Harley-Davidson touring models, based on official installation instructions and manufacturer documentation. The focus is on practical steps, compatibility considerations, and best practices to ensure a safe and durable installation.
Introduction
Harley-Davidson offers a range of horn kits and accessories, including air horns, for riders looking to upgrade their vehicle’s horn system. These horns serve as both functional and aesthetic enhancements, allowing riders to personalize their machines while improving road safety by making their presence more noticeable. Installation of an air horn system, particularly the "Love Jugs" model, involves multiple steps, including bracket mounting, wiring, and ensuring proper clearance from heat and vibration sources.
The installation process is typically designed for experienced DIY enthusiasts or professional mechanics, given the precision required in routing wires, mounting hardware, and verifying compatibility with the bike's existing systems. The instructions provided by manufacturers emphasize the importance of torque specifications, bracket alignment, and avoiding interference with other components such as gas lines and engine parts.
Understanding the Components and Kits
Harley-Davidson air horn kits, such as the Love Jugs, include all necessary parts for installation, including brackets, mounting hardware, and wiring harnesses. These kits are typically sold as complete sets, allowing riders to replace the factory horn or add an auxiliary horn for a more robust sound. The kits also include detailed instructions for assembly and installation, ensuring that users can complete the process with the appropriate tools and knowledge.
One of the key components of the installation is the Frame Mount Kit (FMK), which is recommended for reducing vibration and ensuring long-term durability. The FMK mounts the horn assembly directly to the motorcycle’s frame, as opposed to the engine, which is known to vibrate significantly and can cause wear over time. The kit is engineered with solid stainless steel brackets and is designed to exceed load requirements by a factor of 20:1, ensuring a stable and secure installation.
For motorcycles equipped with water-cooled heads, a specialized Water Cooled Frame Mount Kit (WCFMK) is recommended. This version is designed to accommodate the cooling hoses and other components specific to newer engine models. Riders are advised to consult the compatibility information provided by the manufacturer to ensure that the selected kit fits their specific motorcycle model.
Step-by-Step Installation Guide
The installation process for the Love Jugs air horn system is methodical and requires attention to detail to ensure proper function and safety. Below is a detailed breakdown of the installation steps, as outlined in the manufacturer's documentation.
Step 1: Removing the Existing Horn and Bracket
Before installing the new horn system, the existing horn and bracket must be removed. This involves the following steps:
Remove the Chrome Acorn Nut: This nut secures the horn and horn cover to the mounting bracket. It should be carefully removed to avoid damaging the surrounding components.
Disconnect the Wires: The horn is connected to the bike’s wiring system using two wires. These wires should be disconnected from the horn to prepare for the new installation.
Remove the Bolts on the Horn Bracket: The bracket that mounts the horn to the engine is typically fastened using two large bolts. These bolts are not reused in the new installation and should be removed completely.
Set Aside the Original Assembly: The original horn and bracket assembly can be set aside for now, as it will not be used in the new installation.
Step 2: Preparing and Mounting the New Bracket
The new bracket system is designed to mount the horn to the motorcycle’s frame, reducing vibration and ensuring a more stable installation. The following steps outline the process:
Attach Bracket “A” to the Frame: The new bracket should be placed on the bottom of the frame with the rounded and protruding section facing the rear of the bike. A temporary taping method can be used to hold the bracket in place during installation.
Align the Bracket: The bracket should be centered between the two heads of the engine. Due to the adjustability of the bracket, precise positioning is not critical, but it should be aligned to allow for proper installation of the horn.
Secure the Bracket with Worm Clamps: The bracket is secured using worm clamps, which are adjusted by loosening the drive screw and feeding the unattached end over the frame. The end is then routed through the slots in the base of the bracket and reinserted into the hub of the clamp. The screw is tightened clockwise to secure the bracket in place.
Step 3: Installing the Horn and Cooling System
After the bracket is in place, the horn and cooling system can be installed. This involves the following steps:
Insert the Stud into the Bracket Assembly: A 5/16” x 18 stud is used to secure the horn to the bracket. The stud is inserted into the bracket with the Love Jugs cooling system sandwiched between the chrome horn bracket and the horn cover.
Attach Rubber Washers and Nut: Three 1/4” thick rubber washers are screwed onto the stud to provide vibration damping. The stud is then bolted into the Love Jugs unit and horn assembly using the recommended torque specification of 100–120 inch-pounds on the acorn nut.
Verify Clearance and Alignment: It is important to ensure that the Love Jugs unit is aligned properly and that the wire harness does not come into contact with the engine. A minimum clearance of one inch is recommended to prevent heat damage and vibration interference.
Step 4: Routing the Wiring
The wiring for the air horn system must be carefully routed to ensure it does not interfere with other components and is properly secured. The following steps outline the process:
Locate the Harley Accessory Plug: For Harley Touring models with an accessory switch on the dash, the accessory plug is typically located under the seat and near the front of the battery. The rubber dust plug should be removed to access the plug.
Route the Harness Under the Gas Tank: The Love Jugs wiring harness should be routed under the gas tank and secured using the included wire ties. This ensures that the harness is protected from heat and vibration.
Plug into the Accessory Plug: The harness is then connected to the Harley accessory plug. Before final installation, the ignition should be turned on and the accessory switch activated to verify that the fans are operational.
Alternative: Direct Battery Connection: If a direct battery connection is preferred, the wiring should be carefully routed to avoid contact with the engine. The harness should be secured using the included wire ties and positioned away from heat sources.
Step 5: Final Checks and Adjustments
Before completing the installation, several final checks should be performed to ensure the system is functioning properly and all components are securely in place:
Check for Clearance Issues: Ensure that the gas line and wires do not touch any part of the brackets or engine. A minimum clearance of one inch is recommended to prevent potential damage.
Verify Bracket Alignment: The bracket should be checked for proper alignment to ensure that the Love Jugs are straight and positioned correctly.
Tighten Set Screws: If the installation involves a bracket with set screws, these should be tightened using the provided Allen wrench to secure the rod in place.
Test the Horn System: Before re-installing the gas tank and seat, the horn system should be tested to ensure that it functions correctly. This includes checking the fans and verifying that the horn produces the expected sound.
Best Practices and Safety Considerations
To ensure the longevity and reliability of the air horn installation, several best practices and safety considerations should be followed:
Use the Frame Mount Kit (FMK): As recommended by the manufacturer, the FMK is essential for reducing vibration and ensuring a stable installation. This kit is highly recommended for all compatible models and should be used unless the motorcycle is equipped with a stabilizer rod from the horn mount bracket to the frame.
Avoid Compatibility Issues: Riders should consult the manufacturer’s documentation to verify that the selected kit is compatible with their specific motorcycle model. For example, the FMK will not fit motorcycles with water-cooled heads, and the WCFMK should be used instead.
Secure All Wires and Components: Proper routing and securing of wires is crucial to prevent damage from heat and vibration. All wires should be positioned away from the engine and secured using the provided wire ties.
Follow Torque Specifications: Adhering to the recommended torque specifications is important to ensure that all components are securely fastened without causing damage. Over-tightening can lead to stripped threads or broken components, while under-tightening can result in loose parts and potential failure.
Test the System Before Final Installation: Before re-installing the gas tank and seat, the horn system should be tested to ensure that it functions correctly. This includes verifying that the fans are operational and that the horn produces the expected sound.
Consult a Professional if Needed: While the installation process is designed for DIY enthusiasts, riders who are not confident in their ability to complete the task should consider consulting a professional mechanic. This ensures that the installation is completed safely and correctly.
Conclusion
Installing an air horn system on a Harley-Davidson motorcycle is a rewarding project that enhances both the functionality and aesthetics of the vehicle. By following the manufacturer’s detailed instructions and best practices, riders can ensure a safe and durable installation that meets their customization goals. The use of the Frame Mount Kit (FMK) is highly recommended to reduce vibration and prolong the life of the horn system, while careful routing of wires and verification of compatibility are essential for a successful installation.
Whether replacing the factory horn or adding an auxiliary air horn, the process requires attention to detail and a methodical approach to ensure all components are properly installed and functioning correctly. By following the steps outlined in this guide, riders can confidently complete the installation and enjoy the improved sound and presence of their customized Harley-Davidson.