1949 Entering the Automotive Wiring Harness Business

Sumitomo Electric entered the automotive wiring harness* business in 1949. The Company had learned that the U.S. military stationed in Japan would be procuring wiring harnesses to repair jeeps in Japan. Sumitomo Electric did not have any experience in these products. However, the relevant personnel including those who were responsible for designing and manufacturing the products made strenuous efforts. Eventually, the Company succeeded in delivering wiring harnesses for 500 jeeps. Subsequently, it stopped production temporarily, but resumed the wiring harness business in 1959. Anticipating the future potential of the auto industry, it decided to make a full-fledged entry into the business. To operate this business, Sumitomo Electric was responsible for sales, and Tokai Electric Wire Co., Ltd., one of its affiliates (currently Sumitomo Wiring Systems, Ltd.), was responsible for production. In the 1960s, production expanded quickly due to motorization in Japan. In 1966, Sumitomo Electric developed a high-voltage automotive wire in cooperation with Tokai Electric Wire, and received orders in the following year.

In 1995, Sumitomo Electric and Sumitomo Wiring Systems established a joint venture named Harness System Technologies Research, Ltd. (currently AutoNetworks Technologies, Ltd.) to further enhance R&D and created a “trinity” system.

Based on this system, a Group-based project was launched to develop an aluminum wiring harness in 2006 as many countries sought to curb CO2 emissions. The Company staked its future on this major project. Sumitomo Electric’s superior overall engineering capability was highly evaluated, and the aluminum wiring harness was used in automobiles for the first time in 2010. At present, Sumitomo Electric supplies aluminum wiring harnesses to automakers in and outside Japan. The aluminum wiring harnesses are used around the world to help reduce the weight of automobiles and reduce CO2 emissions.

* Wiring harnesses are arranged throughout an automobile. They are important products to transmit energy and information. They are the automobile equivalent to the blood vessels and nervous system in the human body. For details, refer to the special feature of vol. 02 of id: “Aluminum Wiring Harness: Key Factor in Change of Automobiles and Auto Future”.