The Manufacturing Process of Wire Harnesses

Wire harnesses consist of bundles of wire, cable, or subassemblies, combined with other conductive materials, and they are used to transmit electricity in various applications. The bundling of these components makes it easier to install electrical components for signaling or power transmission. In addition, other benefits of using wire harnesses include increased productivity, lower costs, and improved safety by minimizing trip hazards and wire damage.

What Are Wire Harnesses Used for?

A wire harness, also known as a wiring assembly or cable harness, groups multiple wires, cables, or subassemblies to supply electrical power or transmit signals in many applications.

Wire harnesses have multiple applications and uses that make them suitable for many industries. A few of the main markets that use wire harnesses include the medical, military, and industrial industries. The transportation industry also frequently uses them in automobiles, trucks, buses, and planes. Other applications include industrial equipment, construction machinery, household appliances, and electronics.

The Manufacturing Process of Wire Harnesses

The wire harness manufacturing process ranges from basic to complex, depending on the end product. While it can be challenging, time-consuming, and task-oriented, a streamlined manufacturing process helps maintain efficiency and quality with each wire harness. The following is a breakdown of the different steps of the process and what they entail:


While wire harnesses often appear simple, a clear, accurate design phase is critical to setting production and the manufacturing process up for success. This stage may involve choosing harness components, specifying different colors to identify specific wires, specifying all wire and cable lengths, and various other details.


Following the design stage, prototyping takes place. This entails developing a physical product based on the chosen design specifications. In the process, manufacturers can identify areas for improvement and determine how to approach the rest of the manufacturing process. This helps ensure optimal quality and process performance before beginning the first production run.

Production & Assembly

During production and assembly, manufacturers must meet design specifications and make sure the end product meets quality standards with minimal risk of errors. The production process still heavily relies on manual assembly even as manufacturing becomes increasingly automated.

Throughout this stage, manufacturers typically complete three main steps:

  • Wire Cutting — The first step in the production phase involves cutting wires to their designated lengths using a wire-cutting machine.
  • Stripping and Connections — After cutting, the next step entails stripping the wire ends to expose their cores, which allows for the attachment of connector housings, terminals, or modules.
  • Assembly — The last step is the wire harness assembly process, which involves putting together the wire harness using an assembly board or workbench to put the final product together based on design specifications.


Following the core manufacturing process, manufacturers test the end product for quality assurance purposes. If the product meets quality and performance standards, the manufacturer ships the final product to the client.

Top-Quality Wire Harnesses from Electro-Prep

Various applications require reliable wire harnesses for transmitting electricity/data. If you’re in need of a wire harness for your application, Electro-prep can manufacture custom wire harnesses based on your unique requirements.

To learn more about our wire harness manufacturing capabilities, contact us today. If you would like to get started, request a quote from us and we’ll connect you with one of our experts.

Wire Harness vs. Cable Assembly

Cable assemblies and wire harnesses are often referred to interchangeably because they both provide power to electrical devices. However, they are two different kinds of products.

A wire harness is a bundle of wires organized together by a low-cost exterior wrap or sleeving. The wires are electrically conductive material, such as copper or aluminum. A cable assembly is a collection of cables or wires shielded by a stronger exterior material, like vinyl, thermoplastic, or thermoplastic rubber. Each cable is made up of at least two wires, which are laid out or braided together within the cable jacket.

Here you’ll learn more about wire harnesses and cable assemblies, including their respective applications.

Wire HarnessesWire Harness vs. Cable Assembly: Similarities

The primary functions of both a wire harness and a cable assembly are to protect and organize wires or cables that conduct electrical currents. Both products also come protected by an insulating sleeve made of plastic or rubber, but the strength of this layer depends on whether it is a wire harness or cable assembly. In general, this layer protects the sensitive wires and cables from corrosion, shock, and impacts in their specific environments.

Wire Harness vs. Cable Assembly: Differences

Wire harnesses and cable assemblies are effective in different applications. The materials used in both products are generally the same, but the toughness of these materials differs.

Wire harnesses offer physical support for wires in protected spaces, so their insulating wrap or sleeving—usually made of PVC or plastic—provides sufficient protection for these specific environments. Unlike cable assemblies, wire harnesses are not intended for applications with extreme environmental exposure, such as dust, heat, friction, and moisture. Cable assemblies feature a durable encasement made of thermoplastic rubber, shrink-wrapped thermoplastic, or vinyl to protect electrical components from these harsh outdoor conditions. Cable assemblies are also easier to thread around tight spaces because each bundle of cables are grouped together in one sheath.

In terms of cost, wire harnesses are less expensive than cable assemblies. Wire harnesses require less material and labor to manufacture, and their cost reflects their relatively limited use cases. Cable assemblies offer a higher level of protection in a variety of harsh environments, so they are typically available at a higher price point. 

Wire Harness vs. Cable Assembly: Applications

Wire harnesses are common in these industries and applications:

  • Airplane engines 
  • Commercial and residential wiring
  • Car dashboards
  • Computers
  • Electronics
  • Garage door openers
  • Soda machines

Cable assemblies are used in many industries, including: 

  • Military
  • Aerospace
  • Oil & gas electronics
  • Healthcare

High-Quality Wire Harnesses and Cable Assemblies From Electro-Prep

Wire harnesses and cable assemblies both protect and organize wires that carry electrical signals. However, their differences determine the right application for each one. 

Established in 1977, Electro-Prep is a turnkey contract manufacturer of custom cable assemblies, wire harnesses, box builds, and other custom electromechanical assemblies. As an ISO 9001:2015 certified company, we are committed to high quality control standards, customer satisfaction, and continuous improvement. Contact us today to learn more about our products and services, or request a quote to get your project started.

Contract manufacturer specializing in custom wire harnesses, cable assemblies, box-build, electro mechanical assemblies and custom assembly. ISO 9001:2015 certified. Serving Massachusetts, New England and companies across the USA and Canada. Made in the USA.