Wiring Harnesses for Automobiles

Wiring Harnesses for Automobiles that Connect You to the Cars

Automobiles are operated by a variety of electric controls such as being able to start the engine by pushing one button. Along with the increase in functions for automobiles, the number of electric devices installed is also increasing. The wiring harnesses play a role in connecting those devices and delivering electricity and signals through the entire car. The functions are similar to the blood vessels and nerves of a human body.

Aluminum Harnesses

Complying with the recent requirements of lower fuel consumption, safety, and riding comfort of the automobile, weight reduction of the wire harness (by 20-30 kg per vehicle) has become a more important issue.  Instead of the copper wire which has been conventionally used, "high-strength aluminum alloy wire"  is installed in the engine harness for the purpose of reducing weight and cost. 


Compared with conventional aluminum wire, our "high-strength aluminum alloy wire" exhibits higher strength and higher bending properties, which have been applied to the development of the high-strength aluminum harness.  The  "high-strength aluminum alloy wire" has been employed as the engine harness for the  first time in the world (approximately 20% or more of the number of the wires).  The wire harness has succeeded in reducing the weight and cost to a level lower than those of current products.


The strength and bending properties of the newly developed "high-strength aluminum alloy wire"  are higher than those of copper wire (twice higher than the standard aluminum wire).  This allows thinning of the wire, and application to the vibrating and bending parts of the engine.

Wiring Harnesses for Sliding Door

Employed for the slide door of minivans, conveying electricity (power supply, signal) to electrical components installed in the door either in closed or opened state.


  1. Stable movement track (always moves on the same tracks)
  2. Fits inside the small space inside the door
  3. Prevents extraneous noise


By combining the cable beya the rotating parts and, we can protect the moving tracks and ensure compatibility with various sliding door tracks for opening and closing.

EPB* Harness Integrated with Wheel Speed Sensor

This product is an integration of a wheel velocity sensor and a harness for the EPB (Electric Parking Brake). Sumitomo Wiring Systems was the first in the world to reduce the weight of the product and cut manufacturing costs, by integrating the wheel speed sensor to the harness for the EPB.

Properties of the Wheel Speed Sensor Integrated With EPB Harness

Sumitomo Wiring Systems has integrated the wheel speed sensor and the harness for EPB through application of the technology of the wheel speed sensor, wire, and connector, instead of using the intermediate connectors and double sheath wire.


We realized the integration of the wheel speed sensor and the harness for EPB by combining the 2 core cables for the ABS and 2 core cables for the EPB and converting them into a 4 core cable. By commonizing the components attached to the harness, a reduction of in working hours needed to assemble components and vehicles was realized. In addition, we contributed to weight reduction of the vehicles by simplifying the routing design for the car manufacturing companies.