Automotive industry standards in wire harness design

Apr 3, 2024

Are you a wire-harness engineer or a CAD professional looking to minimize errors in electrical wire harness (EWH) designs? Do you aim to catch potential issues early in the design phase to save time and money for your company? Implementing industry standards in wire harness design is a critical step toward achieving efficiency and reliability. This guide provides a structured approach to adopting automotive industry standards in your EWH design process.

Understanding the importance of wire harness design

The wire harness is an organized set of wires, terminals, and connectors that plays a vital role in "connecting" various vehicle components. As Oakley Miller notes, modern cars have complex wiring systems, and the design process must include a wiring diagram that captures all electrical components, their connections, and wire lengths (Miller). This complexity underscores the need for a meticulous design process that adheres to industry standards.

Step 1: Gathering requirements and specifications

The initial step in designing a wire harness is to gather all necessary information about the vehicle's requirements and specifications. This includes understanding the electrical and mechanical environment in which the wire harness will operate, as well as the constraints imposed by the vehicle's architecture. Manufacturers use schematic diagrams and cable layouts to ensure that all components are accurately represented and that the wire harness meets the final product's specifications.

Step 2: Adherence to industry regulations and standards

To maximize vehicle and component safety, wire harness routing and packaging must adhere to industry regulations and standards. For electrical components in the automotive industry, common UL standards include UL 4, UL 13, UL 44, UL 62, UL 83, UL 1063, and UL 1072, which cover aspects such as armored cables, power-limited circuit cables, and thermoplastic-insulated wires (IEWC). These standards ensure that the materials and components used in the wire harness design are suitable for automotive applications and can withstand the operating conditions.

Step 3: Design and routing best practices

Wire harness design and routing are interdependent processes. Best practices include avoiding sharp bends, ensuring proper strain relief, and securing the harness to prevent abrasion and damage. Routing should also consider maintenance, with adequate service loops and accessibility for future repairs or upgrades (Auto Wiring Pro). These practices help to optimize the wire harness for its installed environment and contribute to the vehicle's overall safety and reliability.

Step 4: Selection of components and materials

The selection of components and materials is crucial in the design process. The increasing diversity of connection systems in vehicles, which now include features like light sensors and advanced driver assistance systems, requires a thorough understanding of the connectors used (Wiringo). Manufacturers must carefully consider the application and environment of the wiring harness to determine the appropriate components and materials.

Step 5: Manufacturing and automation

Traditionally, wire harnesses were manually assembled on a nail board or form board. However, automation is revolutionizing the industry, improving efficiency and productivity. Harness manufacturers must optimize and cost the manufacturing processes, labor, material, and resources required to produce wire harnesses. Digitalization plays a crucial role in this transition, enabling manufacturers to accurately design and develop wire harnesses that meet industry standards.

Wrapping up - The implementation of industry standards in automotive wire harness design is a multi-faceted process that requires attention to detail, adherence to regulations, and incorporation of best practices. By following the steps outlined in this guide, manufacturers can ensure that their wire harness designs contribute to the safety, efficiency, and performance of the vehicles they help to power. As the industry continues to evolve, staying abreast of the latest standards and technological advancements will be crucial for success in wire harness engineering.