10 Types of Wiring Harnesses

Wiring harnesses are used across many industries, including automotive, electronics, marine, aerospace, and military. Each application requires specific adjustments to ensure reliable performance and a precise fit. 

Differences in connector types, conductor and insulation materials, shielding, and wire branching reflect these unique requirements, resulting in a wide variety of harness types. To make sense of them, we will first cover 10 types based on structure and customization, then group them by operating environment and function.

10 Types of Wiring Harnesses

Based on structure and level of customization, wiring harnesses can be grouped into these 10 types.

Closed Bundle Wiring Harnesses

A closed bundle wiring harness gets its name from its sealed branch design. The harness’s individual wires are enclosed in a protective material to safeguard against mechanical damage, moisture, external elements, and EMI. As such, these cable bundles are suitable for rugged or harsh application areas, such as industrial settings, aerospace, marine, and automotive.

Open Bundle Wiring Harnesses

Open bundle wiring harnesses are the opposite of closed bundle cables. They don’t have an additional protective material to enclose the branches, leaving each one with only the protection of its insulation layer. This design makes the wires easy to access for repairs or modifications and reduces the weight of the harness.

Such cable bundles are suitable for signal and communication systems, airframe fuselages, gas turbine engines, and nacelles where repairability and accessibility are important, but there’s not much EMI or exposure to the elements.

Standard/Universal Wiring Harnesses

These prefabricated cable bundles contain insulated and protected wires, with wiring harness connector types that enable easy connections and disconnections. They are used to distribute power, data, and signals between components or control units in general equipment such as cars, electronics, machinery, etc.

Customized Wire Harnesses

Customized wire harnesses are cable bundles designed and built to suit customer specifications. The tailoring process makes the harnesses plug and play in the required applications, and it includes picking the most suitable materials and structures to provide maximum durability, performance, and reliability.

Hybrid/Multi-Branch Wiring Harnesses

Multi-branch or hybrid wiring harnesses consist of a central bundle with one or few wires that branch into a complex wire network. These multiple branches are ideal for distributing signals and power in advanced machines used in applications like agriculture, informatics, and aerospace.

Single Cable Assemblies

Compared to their multi-branch counterparts, single cable assemblies have a single conductor. This setup is suitable for long-distance or high-power transmission applications. The typical types are coaxial cables, FFC/FPCs, battery cables, or ribbon cables.

Overmolded Connector Cable Assemblies

Cable overmolding is a manufacturing process that combines and seals a wiring harness with its connector to form a unified part. Therefore, overmolded cable assemblies provide better strain relief, enhanced durability, dust and water resistance, electrical insulation, and a compact/streamlined design compared to regular harnesses.

Integrated Connector Cable Assemblies

Cable assemblies with integration connectors are ready-to-use components that simplify connecting and integrating with applications and data sources. Designed for high-voltage connectivity, they optimize space while ensuring long-term reliability and peak performance—even in demanding environments. These features make them indispensable for building efficient and durable controllers.

Flat Wire Harnesses

Flat wire harnesses are characterized by a flat cross-section, similar to ribbon cables. This side-by-side wire arrangement forms a parallel multi-signal transmission channel, which is required in internal computer connections, home appliance control boards, and car instruments.

Circular Wire Harnesses

In circular harnesses, wires are arranged parallel around a central axis and enclosed in a sheath. This provides excellent wear and bending resistance, making them suitable for industrial equipment and automotive engine compartments.

Types of Wiring Harnesses by Operating Environment

Wiring harnesses can also be categorized by their operating environment into these five types.

High-Temperature Resistant Harnesses

These wire harnesses are built using special insulation and jacket materials that can withstand the high temperatures produced in industrial furnaces, car engine compartments, and aerospace engines.

Waterproof Harnesses

Waterproof wiring harnesses have moisture-resistant insulations tucked into or fitted with sealed wiring harness connector types. Overmolded cables, for instance, fall into this category, and such harnesses are commonly used in outdoor (such as solar installations), marine, or underwater equipment.

Oil and Corrosion-Resistant Harnesses

Oil and chemicals react differently with wiring harness insulations than water does. Therefore, these wiring harness types have materials like PTFE and FEP as their insulation, with sealing structures across the connector joints to prevent seepage. Such wiring harnesses are commonly used in or near chemical equipment and fuel tanks.

Heavy Duty Harnesses

Heavy-duty wiring harness types are designed for applications that demand high strength, maximum durability, and reliability in high-demand, high-load tasks. The cables must be accompanied by heavy-duty connectors, such as mini-FAKRA, Anderson, ix, and RAST. Typical applications include industrial equipment and agricultural devices.

RF Harnesses

Wiring harnesses deployed in operating environments exposed to high noise must be able to maintain signal integrity inside. So, shielding is necessary on both the cable and the connector. Conformable, low-loss coaxial, 50 and 75-ohm, flexible, and high-performance RF wiring harness types fall in this category, and they are broadly used to transmit high-speed digital signals in telecommunication and military applications.

Wiring Harness Function Types

Wiring harnesses can also be categorized according to their function types, which gives us these three types.

Power Harnesses

Power wiring harnesses are designed to transmit electrical energy with minimal losses. Therefore, they feature highly conductive cores (copper or aluminum) and low dielectric loss insulators.

Signal Harnesses

Signal wiring harnesses are built to deliver data and signals reliably, so they must have high transmission speed, interference deterrence, and signal integrity features. Depending on the variety, these cables can have twisted pair wires or shielding to enable these features. 

Multifunctional Wire Harnesses

Multifunctional wire harness types can transmit power and signals concurrently without internal interference.

FAQ

What types of wiring harnesses are used for agricultural applications?

Heavy-duty, custom, and integrated high-temperature resistant cables. The first type is necessary because agricultural machinery is exposed to mechanical stress, high temperatures, moisture, oil, and chemicals. Custom wiring harness types are used to integrate the old but still useful machinery with new ones, while high-temperature-resistant integrated harnesses are used in engines and machinery.

What types of wiring harnesses are used for aircraft applications?

Aircraft primarily use open and closed bundle wiring harnesses. The former is used on the fuselages to simplify repairs, and the latter is used in other areas exposed to harsh conditions.

What types of wiring harnesses are used for automotive applications?

The engine uses high-temperature, waterproof, and oil/chemical-resistant wires. EVs require high-voltage and integrated cable assemblies instead. Waterproof solutions connect the body and chassis, and sensors , while interior electronics primarily rely on flat wire harnesses.

What types of wiring harnesses are used for marine applications?

Water, oil, and chemical-resistant wiring harness types are used to ensure maximum reliability.

What types of wiring harnesses are used for OEM applications?

OEM wire harnesses are made to match the original manufacturer’s specifications. Based on system complexity, they are classified as customized or standard wiring harnesses.

What types of wiring harnesses are used for robotics applications?

Robots require simplified wiring that can handle multiple bend cycles without failure. Circular wiring harnesses are ideal, especially with multiple cores to transmit power and signals through a single line. However, heavy-duty harnesses are recommended for industrial robots to handle high currents, powerful motors, or extreme temperatures.

What types of wiring harnesses are used for solar applications?

Solar wire harnesses and connectors are constantly exposed to the elements and UV. Heavy-duty solutions are good candidates and better than standard power harnesses placed inside conduit pipes.

Choose The Right Type of Wiring Harness

From the list above, you can see that there are many wiring harness types, which fall into different categories depending on their structure, degree of customization, function, and operating environment. These cable types often overlap in these categories. As such, choosing the most suitable one for your application can be tricky unless you are an expert in this field. A manufacturer like Wiringo can help you here and suggest the necessary modifications to make the harness perform optimally and last in its application area.

Wiringo is an expert at wire harness customization. We ensure the harnesses meet all the required industry standards while making these modifications. Contact us to learn more about our capabilities.