HomeTips & GuidesAuto Wire Harness Cover: Ideal Harness Covers for Car Connector Modules

Auto Wire Harness Cover: Ideal Harness Covers for Car Connector Modules

Auto wire harness cover provide extra protection to your car’s electrical systems, ensuring they are safe from extreme conditions. 

But why do manufacturers require automotive wire harnesses when the power cables also have their covers?  Do these complete vehicle wiring harnesses play any additional particular role? 

Join us as we look at the role of an automotive wiring harness and the respective types of covers available. We’ll also explain the subtle difference between the various kinds of covers. 

Table of Contents

What are Automotive Wire Harnessing Solutions?

An automotive wire harness protection is an encapsulating wire bundle with a robust exterior sheath housing numerous wires and over-molded cables in a car’s electrical system. Its primary roles include the following: 

  • It helps to shield the cables from extreme temperatures and other conditions that can damage them. 
  • Also, it assists manufacturers in setting up electrical systems in an organized manner. 

An automotive wire harness encases numerous wires that still have their covering layer. It is, therefore, handy in ensuring an extra protective layer to the power systems. 

Types of Wire Harness Covers

A mechanic fixing a car's electrical system. 

A mechanic is fixing a car’s electrical system. 

Below are the various forms of automotive wire harnesses and their respective roles. 

Pre-fab Braids

It is typically a polyester monofilament-made cover, although you’re likely to encounter some made of polyethylene or nylon. This type of wire harness is among the most preferred by many automotive companies thanks to its exquisite properties, such as the following: 

  • It has excellent heat resistance and thus forms a dual wall heat barrier when used in covering cables. 
  • The material is durable and flexible. It also doesn’t add significant weight to the systems as it’s typically lightweight. 


The standard looms feature corrugated tubings; others have slits to insert the wires easily. 

Those with slits have tees that cover them up to create a perfect cover. Often most looms in the automotive industry are polyethylene, polypropylene, and polyamide-made. 

Wire Harness Tapes

Color-coded wiring harness with black tape. 

Color-coded wiring harness with black tape. 

It is among the most common harness options, especially when you want a material that takes up minimal space. Tape application is simple, primarily winding it around the wires to create a perfect harness cover. 

However, although it is simple to apply, it doesn’t form a perfect cover like the other harnesses. Moreover, it can be a pricier option, but it remains popular, especially in creating quick-fix covering solutions. 

When choosing a wire harness tape, you’ll need to pick between an adhesive automotive wire cover and self-vulcanizing tape, which is equally effective. 

Braid Weaving Looms

It’s a better harness than the typical loom. The material comprises a typical loom and a woven polyester monofilament impregnation to boost its heat resistance capabilities. The two materials are more durable than a simple loom cover. 

It explains why the braid weaving looms are popular in heavy equipment and those used in harsh environmental conditions.

Pick braid weaving looms anytime you want exemplary abrasion resistance in your harness covers. 

But repairing it is not easy because of the material’s stiffness. Nonetheless, it’s worth its price considering the enhanced protection it guarantees. 

Split Weave Looms

As per their name, they come with splits to enhance the easy insertion of wires into the encasing cover. The primary upside of these harnesses is that they don’t apply significant pressure on the cables. 

Also noteworthy is that they require tape to seal off the ends to prevent the wires and cables from falling out of the cover. 


White Fiberglass Sleeves. 

White Fiberglass Sleeves. 

The two kinds of sleeving materials are polyester and fiberglass. Choose fiberglass sleeving for an ideal auto harness cover in high-temperature environments.

It is also excellent at electrical insulation and is thus suitable for high-voltage cable encapsulations. 

On the other hand, polyester sleeving is the better option for a highly flexible cover with excellent wear resistance.

Installing it is also easy, and you can straightforwardly disassemble the material thanks to its flexibility. 

Heat Shrink Tubing

Heat-shrink tubing over underground cables. 

Heat-shrink tubing over underground cables. 

It is the preferred auto craft wire conduit cover method in airplanes and military equipment because of its lightweight nature.

The material primarily consists of adhesive material on a polyolefin or polyamide and is also halogen-free and thus non-toxic. 

Applying heat shrink tubing is also easy to use; it is recyclable and is available in multicolored types for easy identification. 

Spiral Wrapping

Spiral Wrapping. 

Spiral Wrapping. 

Like heat shrink tubing, it is a popular wire and cable encapsulation technique in the aircraft industry. It features an entry point on which to insert the cables and an exit point for an easy installation process. 

How to Select Cable Protection for Automotive Applications

Above, we have covered the main types of cable protection measures. Here are the critical considerations when choosing the ideal option for sealing your cables and wires. 

Sealed or Open System

A sealed casing. 

A sealed casing. 

Would you like an open system or a sealed one? Each of the options has its fair share of upsides and downsides.

If you choose the traditional automotive split loom method, beware that the covers easily open up, especially when overly flexed. 

This limitation means foreign objects, such as water and debris, can easily enter the cover.

Hence, it is common to cover split looms with tape to shield off the entry of particulate materials, although this process is laborious. 

If you want to avoid the above limitations, the option is to use the  Sealed cable protection systems we listed earlier.

Ensure the materials you use for the sealed systems pass the ingress tests for dust and water jets.

Any harness cover with IP66 and IP68/69K ratings is ideal. 

Location of Harness

A hot car engine. 

A hot car engine. 

You also need to consider where you intend to place your harness, as this is a critical determinant of the type of material you choose.

For instance, a harness to protect wires near the engine compartment must have excellent physical properties such as heat resistance. 

Among the best harness materials for such applications is high-temperature polyamide, which can withstand high heat.

But the application requirements for harnesses for use inside the vehicle are not high as for the above case. 

The most critical consideration for in-vehicle harnessing is using a retrofittable conduit system to facilitate the addition of supplementary cables and wires. 

Material Selection

You can use light harness products for basic applications such as encasing cables and wires inside the vehicle or scenarios without extreme conditions. 

Nonetheless, heavy-wall polyamide cable protection systems are imperative for heavy-duty encasing in high-temperature and rough-use environments. 

Cable Protection System Accessories

Self-lock nuts. 

Self-lock nuts. 

In addition to the typical wire harness materials we covered in the previous section, it’s also imperative to have further accessories to improve the tensile strength of the encasing. 

In addition, they add an extra protection layer, thus keeping foreign matter such as water and dirt at bay. For instance, ideally, you should accompany the harnesses with different types of fittings, such as the following: 

  • Abrasion Rings
  • Fittings with built-in strain relief
  • Divisible lock nuts
  • T junction fittings

Longevity of System

Lastly, how long would you like your harness system to last? It is a critical determinant of the harness grade you’ll pick because you’ll have to choose quality systems for long-lasting systems. 

The alternative is to use wire harness tapes for a short-term solution as you wait to invest in a durable system in the long term. 


Excellent quality harness covers come at a high cost but are worth their pricing as they significantly help protect the cables inside from extreme conditions. 

Always beware of settling on any harness cover without considering its properties and the protection you want. 

Above, there’s a range of different covers for electric vehicle connectors. Some even come as colored tubing material. So all you need is to select an ideal harness based on the above factors.

Hi I am Christa, sales manager of Cloom.

I have extensive expertise and experience in wiring harnesses and I believe I can help you.

And we have a very professional technical team who can clearly understand the customer’s needs and give professional suggestions and solutions after receiving the drawings.

If you also have wiring harness needs, please send me the drawing so that we can give you our quote and start our business.

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