A wire harness, or cable harness is a manufactured arrangement of wires, cables, and connectors that transmit electrical power and signals within a specific device or assembly.  Additional items may be incorporated into the wire or cable harness such as sensors, testing points or terminals, switches, gauges or other components. 

Used across various industries such as automotive, telecommunications, aerospace and more, they are essentially a consolidated bundle of wires that are securely bound together and organized using materials such as sleeves, conduit, tape or cable ties.

Wire harnesses play a crucial role in modern systems and high level assemblies, providing an efficient means of transmitting electronic signals and power while minimizing the risk of electrical interference, damage during assembly and prolonged use, and miss-connections that may happen during a manual wiring process. 

Automated machinery and equipment are often used for high-volume production to improve efficiency and consistency, while manual assembly may be more common for low-volume, high mix, specialized or configure/build to order wire and cable harnesses.

Key Aspects of Cable and Wire Harnesses

  • Structure: A typical wire harness consists of multiple wires of different colors, sizes (gauges), and insulating materials, depending on their specific functions and the environment in which they operate. The wires are cut to precise lengths, stripped at the ends, and terminated with terminals or connectors. Some wires may be left un-terminated for soldering to existing circuitry, or connected to power sources or ground.
  • Connectors: Wire harnesses utilize various types of connectors, such as plugs, sockets, terminals, and pins, enabling the quick and secure attachment of the harness to the device or devices it connects. Connectors provide a reliable interface, allowing for efficient assembly, maintenance, and repair which may not be possible with soldered connections.
  • Bundling and Protection: The wires within a harness are bundled together using techniques such as twisting, braiding, cable tied or taping. Additionally, they may be enclosed in protective coverings like plastic sleeves, heat-shrink tubing, or corrugated looms to safeguard them from issues such as moisture, wear and tear, abrasion, temperature extremes, and other potential sources of damage both during installation and prolonged use of the final application.
  • Routing and Organization: Wire harnesses may be intricately designed to follow specific routes, patterns and fit within the available space of the device, system or assembly. They are often secured to the structure using fasteners such as clips or clamps to prevent movement or vibration-induced wear and tear.
  • Identification and Labeling: To facilitate installation, troubleshooting, and maintenance, the wires within a harness are often identified with labels, tags, or color coding. These markings help technicians during assembly and repair to identify the purpose of each wire, wire bundle, connector and termination and make accurate connections as well as troubleshoot issues.
  • Testing and Quality Control: Wire harnesses undergo rigorous testing to ensure their reliability and functionality. Tests may include checks for continuity, insulation resistance, voltage drop, and signal integrity. Visual inspection is performed to verify the quality of the assembly, including proper crimping, connector insertion, and overall workmanship.  Quality control measures help identify and rectify any issues before installation.

Wire harnesses offer several advantages, including simplified installation, reduced assembly time, improved electrical performance, enhanced system reliability, and better overall aesthetics. They are designed to withstand the demands of their specific applications, providing a neat and efficient wiring solution.