Wiring Harnesses

What is a Wiring Harness?

The wiring harness has been our core business since 1987. Sumitomo Electric Wiring Systems designs and manufactures the highest quality and most reliable wiring harness products for the automotive industry.

A wiring harness is an organized set of wires, terminals and connectors that run throughout the entire vehicle and relay information and electric power, thereby playing a critical role in “connecting” a variety of components. Power and information travel through this network much like the circulatory and central nervous systems of the human body.

As cars continue to provide advanced functions, their component parts increasingly require electronics to save space and meet other requirements. Experts at efficient design and configuring complex circuits, SEWS creates wiring harnesses that contribute tremendously to the development and advancement of car manufacturers around the world.

Technology drives the future

The evolution of the automobile today has transformed it into a highly technical array of systems and components that are designed to add safety, comfort, fuel economy, luxury, and convenience to the driving experience. SEWS develops and delivers intelligent products for today’s intelligent automobiles through our advanced product development process.

Connecting with Innovation


Did you know that automobiles today have a thousand or more connection points for circuits and wires? The central challenge of wiring harness technology lies in designing cost-effective techniques for rapidly and accurately assembling these connections.

Developing new, innovative technologies and understanding efficient design principles have enabled Sumitomo Electric Wiring Systems to design, develop, and manufacture products the automotive industry wants.

SEWS is an automobile maker’s one-stop-shop for electrical distribution systems, not just components and parts. First, we listen to our customers. We take the time to understand their vision, requirements and specifications – cost, size, performance, quality, and time to market. Then, we use our research and engineering know-how to develop solutions that are not only innovative, but also affordable. Most importantly, we draw upon our systems expertise to streamline the entire product development process, from concept to prototype to manufacturing and delivery.