MOTORCYCLE WIRING 101

The realm of motorcycle wiring is often perceived as a labyrinthine enigma by many, a domain where chaos reigns supreme. Yet, in the midst of this seemingly convoluted world, there exists a maverick figure named Joe Tessitore. Joe, unlike the majority of bike builders who shudder at the mere thought of dealing with motorcycle wiring, possesses a unique affinity for it. In fact, he revels in it. It’s not just a task for him; it’s an art form, and it constitutes the cornerstone of his thriving enterprise. So, in our quest to unravel the intricacies of the motorcycle electrical system and to provide a comprehensive guide for rekindling the life force of your beloved two-wheeled companion, we turn to none other than Joe.

Embracing the Sparks: Joe’s Journey into Motorcycle Wiring

Joe Tessitore’s passion for motorcycle wiring has not only transformed his life but has also become a beacon of knowledge for those who dare to venture into this electrifying territory. It’s an area where circuits, wires, and connections come alive, breathing energy into a dormant machine. For Joe, this is where the magic happens.
Demystifying the Motorcycle Electrical System
In our pursuit of understanding, Joe offers us a roadmap through the intricate web of motorcycle wiring. He unveils the secrets, deciphers the codes, and simplifies the most cryptic aspects of the electrical system. This isn’t a daunting journey into the unknown; it’s an educational voyage where we explore the inner workings of your bike’s heart.
Resurrecting Your Motorcycle: A Step-By-Step Tutorial
Joe’s expertise isn’t confined to the esoteric realms of wiring theory; it extends to the practical realm of application. In his tutorial guide, he takes you by the hand and walks you through the process of breathing life back into your motorcycle. Whether your bike has been sitting idle for years or you’re a newbie looking to understand the intricacies of wiring, Joe’s instructions are your compass on this journey.
From unraveling the mysteries of your motorcycle’s electrical system to the practical steps of sparking your ride back into existence, this guide is your comprehensive manual for embracing the electrical heartbeat of your motorcycle. It’s not just about resurrecting your bike; it’s about empowering you with the knowledge to become a true custodian of your two-wheeled companion.
So, if you’ve ever gazed upon the tangled wires of your motorcycle with trepidation, or if you’ve yearned to gain the skills to reanimate your ride, join us as we delve into the electrifying world of motorcycle wiring, guided by the indomitable spirit of Joe Tessitore. Your bike’s destiny is in your hands, and Joe is here to illuminate the path.
Undoubtedly, one of the most underestimated, overlooked, and often sidestepped aspects of crafting a bespoke motorcycle is the intricate world of the electrical system.
You may invest copious amounts of your time and hard-earned cash into crafting a high-performance engine or shaping the most aesthetically pleasing lines, but in the absence of that crucial spark, all your efforts culminate in little more than an ornate paperweight.
Enter the unsung hero of the two-wheeled realm, the motorcycle wiring harness. Among the plethora of elements that contribute to your ride’s functionality, this unassuming component takes center stage. In many instances, those who delve into the world of custom motorcycles encounter factory wiring harnesses that bear the scars of time and neglect—snipped, spliced, taped, cracked, and bruised from the touch of countless previous owners.
In this tutorial, we shall bid adieu to the battered remnants of factory wiring and embark on a journey to create a minimalistic, no-frills wiring harness—one that will suffice to set you on the open road, designed to cater to the needs of most vintage motorcycles.
Let’s commence our exploration of the essential components for your motorcycle’s wiring:
1. **A State-of-the-Art Regulator/Rectifier:** This ingenious device takes the alternating current (AC) generated by the stator and transmutes it into direct current (DC) for charging the battery. Beyond this critical function, it acts as a sentinel, safeguarding your electrical system from voltage spikes that could wreak havoc. A quality regulator/rectifier, obtainable from reputable manufacturers like Rick’s Motorsport Electrics, should be a top priority. This component is often found beneath the seat or concealed within one of the side covers, and upgrading it is one of the simplest yet most effective enhancements you can make. Factory versions often underperform, and the chances are that the stock unit is either defunct or approaching its demise.
2. **Transition from Points to Electronic Ignitions:** The transition to electronic ignitions represents a pivotal leap in the evolution of your motorcycle’s electrical system. Traditional points-based ignitions, while functional when meticulously tuned, demand periodic maintenance and a knack for precise adjustment. To obviate these concerns, a plethora of riders opt for electronic ignition units that demand far less attention once installed. Among the most prevalent options are the Pamco and Dyna units, known for their affordability and remarkable performance. Notably, they also eliminate the cumbersome old condensers that all too often succumb to failure, further underscoring the wisdom of this upgrade.
As you venture into the realm of custom motorcycle creation, remember that beneath the dazzling exteriors and powerful engines lies a web of wires and components, holding the key to your machine’s vitality. Pay heed to these foundational elements, and your ride will not only look the part but also deliver the performance you crave.

When delving into the intricate world of motorcycle wiring, it’s imperative to recognize that your choices can significantly impact your bike’s performance, safety, and overall aesthetic. Whether you’re a seasoned rider or a passionate enthusiast, ensuring the proper electrical components is paramount. Let’s explore some key elements that can elevate your motorcycle’s wiring system.

Ignition Precision:

Optical ignition systems, such as the cutting-edge Power Arc, cater to those with discerning tastes and deep pockets. These systems deliver an impeccably timed spark, optimizing power output for riders who dream of conquering the track or those simply seeking the finest performance.

A Fresh Start with Batteries:

A motorcycle’s beating heart, the battery, is indispensable. If your bike’s charging system has shown signs of weakness or if it has been dormant for an extended period, it’s not worth taking chances. Embrace a new battery to ensure your machine’s reliability and eliminate unwelcome surprises on the road.

The Art of Quality Wiring:

When it comes to wiring, quality reigns supreme. Opt for at least 16-gauge, thin-stranded copper primary wire; never resort to solid core wires designed for home use. Those ubiquitous red and blue crimp connectors may suffice, but if you seek a professional finish that resonates with precision, look no further than Vintage Connections. Their supplies not only do the job efficiently but also harmonize with existing connectors on your bike, ensuring a seamless integration.

Optional Enhancements for the Visionaries:

While not mandatory, these enhancements can eliminate potential pitfalls in your electrical system, bolstering your bike’s reliability:

  • Ignition Coils: These powerhouses drive the spark plugs, often residing beneath the gas tank. Many motorcycles still house serviceable coils compatible with newer electronic ignitions, although you may need to adapt their mounting brackets to fit aftermarket coils like those from Dyna or Emgo.
  • Upgraded Stator: The stator, located under the left side cover of the engine, generates the energy required to run your electrical system and maintain your battery’s charge. Some older motorcycles suffer from weak charging systems that deteriorate over time. If upgrading the regulator/rectifier falls short, consider a stator replacement from reputable brands like Rick’s or Hugh’s Handbuilt. These units provide a substantial boost in charging power, and in certain cases, enable battery-free operation, a boon for kickstart-only motorcycles.
  • Motogadget Marvels: For those who demand the pinnacle of motorcycle wiring, Motogadget accessories are the gold standard. The m-Unit, a self-contained and programmable electrical core, is a revelation. It renders fuses obsolete, employing electronic circuit breakers to safeguard your electrical components. A weekend project for those with some patience, it connects seamlessly to your battery, allowing you to distribute power to every electrical element on your bike – from headlights and taillights to turn signals and horns. Motogadget even offers an integrated alarm system for added security.

Tailoring Your Motorcycle Wiring:

In the world of motorcycle wiring, your choices are pivotal. By selecting the right components and enhancements, you can create a well-balanced, high-performance, and visually stunning electrical system that complements your bike’s overall aesthetic. Whether you’re a dedicated racer or a rider with an eye for detail, these choices will impact your motorcycle’s performance and reliability in profound ways.

Now that we’ve covered the fundamental aspects of motorcycle wiring, let’s dive into the intricacies of this electrical art.
Imagine the wiring of a motorcycle as a vital circle, a life force that powers your two-wheeled companion. It all begins at the battery, where power emerges from one terminal and embarks on a journey, passing through an array of electrical components (lights, horn, coils, and more) before ultimately returning to the battery’s opposite terminal. This circle must remain unbroken; otherwise, something vital within your motorcycle’s electrical system will cease to function. Let’s break down this process step by step:
1. To establish the grounding point, connect the negative (-) terminal of the battery to a clean, bare metal section of the motorcycle’s frame, preferably an engine mounting point. This strategic connection transforms the entire frame into a grounding point, allowing every light or accessory to find its grounding anywhere on the frame. On a kickstart-only bike, this wire can be of a similar size as other wires (14-16 gauge). However, if you’re dealing with an electric start system, this wire must be much thicker (4-6 gauge).
2. The positive (+) terminal connects to an inline fuse holder. Modern blade-style fuses are preferable to the older glass tube fuses, with a rating between 20 to 30 amps.
3. From the fuse holder, extend a wire to your ignition switch, whether it’s a keyed switch or a discreetly hidden toggle switch. It’s crucial that the switch can handle at least 30 amps since all power to your motorcycle’s electrical system flows through it.
4. Establish a central power wire, the “backbone,” running from the front to the rear of the bike. This backbone will serve as the power source for all accessories. Begin by connecting the remaining wire from the ignition switch to the backbone wire.
5. Attach the hot wire from the headlight to the backbone wire and ground the other wire to the frame. Perform the same connections for the taillight.
6. Your front and rear brake light switches each have two wires. One wire from each switch connects to the backbone wire, while the other connects to the third wire on your taillight (the brake light wire).
7. Coils typically have two small input wires. Attach one wire from each coil (if you have more than one) to the backbone wire. The remaining wire connects to your points or chosen electronic ignition. The thicker wire with the cap connects to the spark plug – a basic yet crucial element.
8. If you’re using an electric start system, connect one of the lugs of your starter solenoid to the positive (+) battery terminal using a 4-6 gauge wire. The other lug should connect to the thick wire leading to the starter. The solenoid will also have two small wires or connector tabs. One of these connects to the backbone wire, and the other connects to your starter switch. If not already grounded through the handlebars, ground the other side of your starter switch to the frame.
9. Let’s not forget the charging system. Your new regulator/rectifier should have three yellow input wires. These connect to the wires coming out of the stator, typically from the left side of the engine (the order doesn’t matter). Connect the red wire from the reg/rec to the positive (+) battery terminal and the green wire to the negative (-) terminal.
In some cases, like with CB750s, you may encounter an additional white field coil wire bundled with the yellow stator wires. For bikes with this setup, the reg/rec will have extra wires that connect to the field coil wire and the powered backbone wire. Always consult the instructions that came with your specific unit.
10. And there you have it! Turn the key, press the starter button, and savor the sweet symphony of success. Congratulations, you’ve successfully rewired your bike!
Now, keep in mind that this is a basic system to get your motorcycle up and running. It doesn’t encompass more advanced components like turn signals, a horn, or indicator lights. If you plan to install these additional features, follow the same formula: draw power from the backbone wire, route it through your switch, and onward to your desired light or accessory.
Lastly, as you wrap up your wiring masterpiece, choose your preferred method for securing the wires. Some opt for heat-shrink tubing, while others favor electrical tape or plastic wire looms. Regardless of your choice, ensure the wires are securely fastened and kept away from sharp edges or heat sources, as broken or melted wires are the most common culprits behind electrical failures in motorcycles. Your dedication to a well-organized and safely wired bike will pay off in reliability and peace of mind on the open road.