……and What is the Difference?
Table of Contents
We get a lot of calls from customers fed up chasing electrical gremlins and, upon questioning, we realize that they are troubleshooting an old, brittle and potentially hacked on original wiring harness. Deciding to replace the wiring harness is an easy choice in such situations and we stock a vast inventory of wiring harnesses to suit various years, makes and models.
Now that you’ve decided to replace your harness and you’ve cracked open your parts book to locate the Lucas part number for your harness, when you search our webstore for that part number you’ve found we offer 2 different harnesses for your application: A Genuine Lucas harness and another Unbranded one for a few dollars more. The choice may seem easy, why not save a few dollars and buy the actual name brand Lucas harness – Win / Win, right? Maybe not, so let’s discuss each option before you make your choice.
The choice may seem easy, why not save a few dollars and buy the actual name brand Lucas harness – Win / Win, right? Maybe not, so let’s discuss each option before you make your choice.
Note; For the sake of this article, we are going to be referencing a 1969-70 Triumph 500 & 650 replacement wiring harness Lucas PN# 54957095 in examples and picture references, while some of the specifics we discuss may relate directly to 1969-70 Triumph twins, the core information rings true for other years and models
Genuine Lucas Brand 54957095 G Wiring Harness
“It has all of the same connection points that were fitted to the original main harness and correct wire lengths to make the proper connections, all wrapped up in a woven cloth wrap as original.”
The Lucas brand harness PN# 54957095 G (we use the ‘G’ extension to denote “Genuine Lucas” ) is a UK made cloth wrapped wiring harness delivered in a Lucas box with all connections to replace the main harness on Triumph 500 & 650 Twins 1969-70 including T120 Bonneville’s, TR6R Tigers, TR6C Tigers, T100R Daytona’s and T100C Tigers . It has all of the same connection points that were fitted to the original main harness and correct wire lengths to make the proper connections, all wrapped up in a woven cloth wrap as original. In comparing the harness to your original one, you may ask yourself a few questions:
- Why is the accent color on the woven cloth wrap is different than mine and even different than the harness pictures on your website? Did I receive the incorrect harness?
Accent color in no way indicates that the harness isn’t correct for your bike or that you’ve received a different harness than ordered, the outer cloth accent color can vary from batch to batch. We have no control over this accent color and are not able to order you a harness wrapped with a specific accent color. If you absolutely need a specific accent color for your bike, please call us prior to ordering and we can verify the accent color of our stock.
- What is going on with the ‘bullet’ connectors? They look different.
The male “bullet” connectors used on the Lucas Brand harnesses are not the same ones used on the original Lucas harnesses built in the 1950s-80s. The Lucas brand harnesses use a similar type male connector that is crimped to the wire sheath then soldered to the wires, but they aren’t the same Lucas bullets you are probably familiar with as a British motorcycle owner. The best way to describe them is that they are cross between a Japanese type compression male connector and a true Lucas bullet connector.
- Do the insulators on the spade connectors make the spade connectors look fat?
Original harnesses used spade terminals for certain connections such as the warning lights, rectifiers, ignition coils, etc. Originals typically had a small rubber insulator to cover the connection, the modern Lucas harnesses instead rely on larger hard plastic connectors. In theory, this isn’t much of an issue; plastic is an insulator much like rubber. In practice, the larger size and lack of flexibility can lead to the need for additional “fettling” when you are fitting the connectors to their landing areas. For connections in fairly open areas (such as the rectifier) this isn’t that big of a deal as there is plenty of extra space, but for connections in tighter areas (for example inside the headlight for the warning lights), the insulators can become a frustration as they are too big to easily clear other objects. One solution when working with these connectors is to cut off the insulators entirely and replace them with some heat shrink tubing to act as insulator, another option is to remove the spade connectors and re-terminate with original type spade connectors and jackets (not supplied, you would need to source them additionally), being careful not to cut them too far back to make connections properly. If you opt to replace the connectors altogether, the money you save on the less expensive Lucas brand harness may get used up quickly.
Is a wiring diagram included?
Yes, Lucas does include a full color, easy to follow wiring diagram with every harness and the harnesses do follow the OEM color codes. The wire colors may be a different shade than original however, but we still recommend having a workshop manual on hand with the original wiring schematic for your model when installing, you’ll want to reference for the wires not shown on the enclosed diagram
Wait a minute, I’m missing some connectors. I thought I was buying a complete harness?!
Your purchase is for a MAIN wiring harness, sundry sub-harnesses will need to be used in conjunction with the original harness to complete installation. Because manufactures often used the same main harness for multiple models during a specific year, the amount and type of sub-harnesses vary from model to model. Depending on your model you may also need some or all of the following to complete installation:
- Taillight harness
- Points lead
- Instrument bulb holder
- Headlight bulb holder
- Pilot light bulb holder
- Warning light bulb holder
- Another note, for some models such as the 1971-72 Triumph 650 twins a 2-part harness (main and headlight) was employed in addition to sub-harnesses. In those instances, you’ll need to purchase both the main and headlight harnesses separately, along with any other necessary sub harnesses
Our Unbranded 54957095 Wiring Harness
“Like the Genuine Lucas harnesses, these are cloth wrapped with proper length wires to make the connection points, will fit multiple models as listed, and are made in the UK.”
Unbranded must mean generic and lesser quality, correct? Things aren’t always so cut and dry, and this is a perfect instance. From our website our unbranded harnesses are easily identified as we not only indicate the OEM Lucas part number but also an internal TBS part number to differentiate them from the Lucas brand (in this instance we list both 54957095 and TBS-6004C for part numbers).
Like the Genuine Lucas harnesses, these are cloth wrapped with proper length wires to make the connection points, will fit multiple models as listed, and are made in the UK. Regarding the specific topics covered above for the Lucas brand harness, differences between and similarities to this harness and the Genuine Lucas harness described above are the following:
- Accent Color – again, we source these already assembled and have no control over the accent color which may be both different than the pictures of them on our website and different than the existing one on your bike.
- Proper Bullet Connectors! This harness is fitted with the correct Lucas bullet connectors as original
- Rubber Spade Connector Insulators! This harness features the proper spade connectors and the flexible rubber insulators including the right-angle connections when applicable.
- Wiring Diagrams are not included with these wiring harnesses; however, they do follow the OEM color scheme, so you’ll need to rely on the Schematic in your workshop manual. If you are comfortable reading schematics and have an appropriate workshop manual this will be a breeze. If you are not comfortable reading schematics and/or don’t have a workshop manual, you’ll have an uphill battle ahead of you.
- Again, this is only the MAIN harness, you’ll also need to reuse your existing or purchase any sub-harnesses separately.
“I have replaced my points with an electronic ignition and/or installed a solid-state Regulator…”
Whether you still have the original points ignition or have upgraded to a modern electronic ignition shouldn’t affect your decision in choosing wiring harnesses. Likewise, for replacing the stock rectifier and Zener diode with a solid-state regulator. Both the Unbranded and Genuine Lucas harnesses replace the original harness – that is they were built to install with a points ignition and rectifier / Zener diode in mind. You’ll need to install the new harness as if you still have the stock ignition and charging components fitted and then follow the instructions provided with your electronic ignition and / or regulator to complete installation.
Which harness one should I buy?
We’ve done our best to outline in this article the features of each brand wiring harness and both the similarities and differences between the 2, now it’s time for you to weigh this information and make the decision which brand best fits your needs. When you purchase the correct harness for your application and install it competently, either brand will get the job done and provide you with years of service.
If you are a purist and want the closest harness to OEM, ironically the Unbranded harness is the better option for you. If you are on a budget and want to save the few dollars or you value having an easy-to-follow full color diagram to guide the installation, you may opt for the Genuine Lucas brand harness. We also have bullet connectors: Electrical Connectors For Classic British Motorcycle
Questions or concerns? Call us at 720-570-7884 or email orders@thebonnevilleshop.com