What Are Wiring Harnesses?

What are wiring harnesses, and what significance do they have for electrical and electronic (E/E) device designs? A wiring harness is a protective outer covering or sheath that holds a group of electrical wires or cables together.

For many applications, wiring harnesses are an ideal way to simplify and standardize the assembly of components that require complex wiring systems. Installers can work with the wires as a pre-assembled unit rather than attaching and configuring each one separately within the device. This improves product uniformity and reduces the chances that any connections are skipped.

The design of a custom wiring harness must take several factors into account, including the number and type of signals being transmitted, voltage requirements, and environmental conditions like exposure to extreme temperatures, corrosive substances, dirt, or water. 

Wiring harnesses have many advantages for E/E devices and components, such as:

• Organizing device wire layouts
• Simplifying workflows
• Easy identification of wire assemblies
• Reducing wire and cable clutter at workstations
• Easier troubleshooting
• Reducing electric shock risk during wiring
• Maximizing space for airflow and components inside devices

Materials for Wiring Harnesses

What are wiring harnesses made of? It’s essential to select a sheath material that meets the specific needs of the application, such as thickness and flexibility, thermal insulation, moisture resistance, chemical resistance, temperature protection, or UV resistance. Common choices include:

• PVC
• Vinyl
• Thermoplastic elastomers
• Polyurethane
• Polyethylene

Cable Harness Vs. Wiring Harness

A common question customers ask is, what is the difference between a cable harness and a wiring harness? They have similarities, but there are some notable differences.

Cable assemblies tend to be used with point-to-point wiring connections. They may include multiple legs or loopbacks; however, in general, they are a pre-bundled group of cables or wires.

Wire harnesses are generally more complex and are an excellent choice for creating a custom group of wires or cables within a device or component. Designers have the ability to include exactly the wires or cables needed for the application and plan out how they should be routed on installation. 

Where Are Wiring Harnesses Used?

There are many applications for wiring harnesses across industries. In any situation where handling numerous separate wires becomes cumbersome or counterproductive, wiring harnesses are an effective solution. They are also critical in protecting delicate wires and connections from damage and environmental conditions.

The following are examples of industries and applications that depend on wiring harnesses to simplify and organize complex wire systems:

• Automotive, aviation, and transportation: Vehicles use wires and cables to relay electrical signals for sensors, control units, lights, actuators, batteries, and more. Harnesses also provide protection against the elements and corrosion.
• Telecommunications: Harnesses for data transmission wires minimize wiring errors while protecting wires from harsh operating conditions and temperature extremes. 
• Flat screens and control panels: Harnesses keep wires and cables compact and neatly grouped in small spaces like thin screen assemblies and panel instrumentation.
• Durable IT equipment: In heavy industrial and military settings, harnesses protect sensitive electronics from dust, weather, and abrasions. 

• Industrial machinery, manufacturing, and construction equipment: Harnesses keep similar wires together and located away from moving parts, heat, exhaust fumes, and other hazards.
• Home appliances: Wiring harnesses streamline appliance assembly in factories and for professional appliance installation.
• Medical equipment and devices: Harnesses keep exposed and enclosed wires away from staff and patients and protect wires from dirt, liquids, and physical damage.

Learn More About Custom Wiring Harnesses From MarVac Assemblies

MarVac Assemblies helps your team make short work of complex electrical connections and assemblies with a range of products and services. We specialize in custom wire harness assemblies, supporting the safe and efficient wiring needs of numerous industries. Additional capabilities include wire processing, sleeving, box builds, value-added electronic component assembly, soldering, kitting, packaging, and more. 

Contact us to learn more about our services, or request a quote to connect with our experts about your next wiring application.

Applications for Wire Assemblies

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A wire assembly, also referred to as a wire or a cable harness, is an organized and integrated cable arrangement within an insulating material intended to carry signals or electrical power. Most standard harnesses contain as few as three discrete elements, whereas traditional assemblies have more wires and other passive (and possibly active) components. They are designed to simplify the manufacture of a larger part and are based on the equipment’s geometric and electrical requirements in which they will be installed.

Wire assemblies are widely used in many industries — including food and beverage service, automotive, electronics, and construction equipment — as well as in manufacturing washing machines, dryers, refrigerators, and other household appliances. They also provide efficient and cost-effective electrical device and equipment solutions, significantly improving their performance, durability, and reliability.

Here are some of the applications of wire harnesses in common industrial sectors:

Manufacturing Processes

Most fully automated assembly and production lines in modern manufacturing factories and warehouses are powered by complex wiring, power cables, and network systems. They link power and signal transmission lines that regulate multiple systems across the same area or throughout the manufacturing line. They also ensure that connectivity is maintained and that cabling and wiring are thoroughly sealed to guarantee that production is fully optimized.

In addition, wire assemblies are used when the same cables are required to simultaneously serve signal and power conductor functions. Manufacturers bundle these working cables together because a single faulty wire can cause significant damage to the entire system.

Communication Systems

Efficient information exchange requires a framework capable of transmitting and receiving data instantly. Because of this, communication systems rely on specially designed wire assemblies for a broad range of technologies and applications, including routers, modems, hotspots, auxiliary devices, and other related devices.

Automotive Applications

Control systems and electrical components are heavily used in automobiles to transmit signals and power for engine revving and ignition. Such signal transmission is part of the extensive wiring network that allows vehicles to start. Automotive manufacturers use wire assemblies to link up the vehicle’s engine management system, power steering and brakes, electric windows, air conditioning system, and other components.

Medical Industries

The medical industry relies on durable, flexible, and biocompatible wire assemblies to ensure that devices function correctly and effectively. These harnesses are primarily used in electronic medical equipment, such as defibrillators, pacemakers, drills, and imaging or radiological devices. Aside from that, these assemblies come in various sizes and shapes. They are also distinguished from other wire harnesses used in other industries as they must be bio-sensitive and comply with FDA regulatory controls and guidelines.

Military Purposes

Wire harness capabilities must consistently meet the Department of Defense’s (DoD) specifications for military purposes. They are designed for extreme conditions and environments and must be constructed with wires, connectors, and terminals specified and approved for use in harsh military settings. Military communications equipment, antenna systems, and control panels are the most common applications for wire assemblies.

Custom Wire Harness Assembly From MarVac Assemblies

MarVac Assemblies has wire processing equipment for all kinds of insulating materials! We can work with solid or stranded wire in gauges ranging from 2 to 24 AWG, and we offer high-quality custom processing equipment and wiring harness services that meet WHMA/IPC-A-620 industry standards.

Our equipment and processes are usually applied to assembled products, such as power supplies, welders, heaters, refrigeration equipment, lighting fixtures, circuit boards, and off-road vehicles. Get to know MarVac Assemblies better by getting in touch with our team today, or request a quote to get started on your next wire harness project!