Harley Single Fire Coil Wiring Diagram

Harley Single Fire Coil Wiring Diagram

Hello readers! In this article, we will discuss the Harley single fire coil wiring diagram, a crucial aspect of Harley-Davidson motorcycles. The wiring diagram is essential for understanding the electrical system and correctly connecting the ignition coil. Let’s explore this topic in detail.

1. Understanding the Single Fire Ignition System

The single fire ignition system is a popular choice among Harley-Davidson riders due to its improved performance and reliability. Unlike the stock dual fire ignition system, the single fire system delivers a spark to each cylinder individually, resulting in better combustion and power delivery.

2. Components of the Single Fire Coil Wiring Diagram

The single fire coil wiring diagram consists of several components, including the ignition switch, coil, spark plug wires, and the ignition module. Each component plays a crucial role in the ignition process, ensuring proper firing of the spark plugs.

3. Wiring Connections

Properly connecting the wiring is essential to ensure the ignition system functions correctly. The wiring diagram provides a detailed guide on how to connect the ignition switch, coil, and other components. Paying close attention to wire color codes and connections is vital to avoid any electrical issues.

4. Benefits of the Single Fire Coil Wiring Diagram

The single fire coil wiring diagram offers several benefits. Firstly, it improves the overall performance of the motorcycle by delivering a stronger and more consistent spark to each cylinder. This results in better throttle response, increased power, and smoother operation.

Secondly, the single fire coil wiring diagram allows for easier troubleshooting of ignition system issues. By following the diagram, riders can quickly identify and fix any wiring or component-related problems, ensuring their motorcycle runs smoothly.

5. Drawbacks of the Single Fire Coil Wiring Diagram

While the single fire coil wiring diagram has numerous advantages, it also has a few drawbacks. One of the main concerns is the increased complexity compared to the stock dual fire system. Riders need to have a good understanding of the electrical system and proper wiring techniques to install and maintain the single fire system.

Additionally, upgrading to a single fire ignition system can be more expensive than sticking with the stock setup. Riders need to invest in a compatible coil and ignition module, which adds to the overall cost. However, many riders believe that the performance gains justify the additional expense.

6. Alternative Wiring Options

For riders looking for alternative wiring options, there are a few choices available. Some opt for the dual fire ignition system, which is the stock setup on most Harley-Davidson motorcycles. While it may not offer the same performance advantages as the single fire system, it is a reliable and cost-effective option.

Another alternative is the programmable ignition system, which allows riders to fine-tune the ignition timing and other parameters. This option is popular among performance-oriented riders who want complete control over their motorcycle’s ignition system.

7. Harley Single Fire Coil Wiring Diagram – Complete Guide

Component Color Code Connection
Ignition Switch Red Connect to positive battery terminal
Coil Black (Primary), Orange (Secondary) Connect primary wire to the ignition switch, secondary wire to spark plug wires
Spark Plug Wires Various colors Connect to spark plugs and coil
Ignition Module Green Connect to coil and ignition switch

8. Frequently Asked Questions (FAQ)

Q: Can I use the single fire coil wiring diagram on any Harley-Davidson motorcycle?

A: The single fire coil wiring diagram is compatible with most Harley-Davidson motorcycles. However, it is always recommended to consult the specific model’s manual or a professional for accurate wiring information.

Q: How can I troubleshoot ignition system issues with the single fire coil wiring diagram?

A: If you experience any ignition system problems, start by checking the wiring connections according to the diagram. Ensure all connections are secure and wires are not damaged. If the issue persists, consult a professional for further assistance.


In conclusion, the Harley single fire coil wiring diagram is a crucial resource for Harley-Davidson riders who want to upgrade their ignition system. While it offers several performance advantages, it requires proper understanding and installation. Always refer to the wiring diagram, follow the instructions carefully, and consult professionals when needed to ensure a reliable and efficient ignition system.