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5 Causes of a Faulty Wiring Harness

A faulty car wiring harness can lead to a myriad of problems, including poor performance, device malfunctions, and even fires. By understanding the main causes of cable harness faults and taking preventive measures, you can ensure the longevity and reliability of your electrical systems.

Regular inspections, proper installation, and adherence to industry standards will help you avoid these common issues and keep your devices running smoothly. If you’re starting to notice issues with your cables, it may be time to look for a classic car wiring harness replacement service in Orange County, CA, and avoid facing serious consequences.

How long should a wiring harness last?

The lifespan of car wires depends on various factors, including the quality of materials used, the manufacturing process, environmental conditions, and usage patterns. Generally, a well-made cable harness should last for many years, if not the lifetime of the vehicle.

In automotive applications, a wiring harness can last for 15-20 years or even longer, as long as it is not exposed to excessive heat, moisture, or physical damage. In other applications, such as consumer electronics or industrial machinery, the lifespan may vary based on specific conditions and usage patterns.

What causes car wiring harness to go bad?

A cable harness is an essential component of a car's electrical system so it must be replaced if not functioning properly. It is an organized bundle of wires, terminals, and connectors that transmit power and information through a vehicle or device. Despite its importance, wiring harnesses are often overlooked when it comes to maintenance and inspection. Here are the 5 main reasons behind their malfunctioning.

Manufacturing defects

One of the primary causes of a faulty wiring harness is manufacturing defects. These defects can include poor-quality materials, incorrect assembly, or inadequate insulation. Manufacturing defects often lead to short circuits, open circuits, or intermittent connections, which can result in a malfunctioning device or even a fire.


Corrosion is another common cause of cable harness failure. Exposure to moisture, road salt, and other chemicals can lead to the corrosion of wires, terminals, and connectors. This corrosion can cause increased resistance, which can result in poor performance or even complete failure of the wiring harness that will prevent your car from starting.

Vibration and physical damage

Vibration and physical damage are also significant contributors to wiring harness faults. Constant vibration from a vehicle's engine or rough road conditions can cause the wires to rub against each other or nearby components, leading to insulation wear or broken wires. Physical damage can also result from collisions or improper handling during installation or maintenance.

Heat and thermal degradation

Exposure to high temperatures can cause thermal degradation of the cable harness, leading to insulation breakdown and wire damage. This can create short circuits, open circuits, or intermittent connections, potentially causing device malfunctions or even fires.

Rodent damage

Rodents, such as mice and rats, can be a surprising cause of wiring harness faults. They are known to chew through insulation and wires, causing short circuits, open circuits, or intermittent connections. Rodent damage can be challenging to diagnose, as it often occurs in hidden or hard-to-reach areas.

Who should be my first choice for classic car wiring harness replacement service in Orange County, CA?

If you need someone to do a complete job on your cable harness but don’t know who to turn to, sweat no more! Chimera Motors is your go-to repair shop with high mileage when it comes to all types of classic car fixes and upgrades.

Use the opportunity to go for a walk down the Newport Pier because once we finish whipping your machine into shape you will find it very hard to resist the pull of your souped-up ride. Drop by our shop today and entrust your baby with our meticulous technicians!


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