Common Mistakes to Avoid in DIY Cable Wire Harness Assembly

A wire harness is an organized collection of wires bound together. Electrical tapes, straps, and wire lacing bind the wires together. It is an electrical system designed to supply electricity to any application. Therefore, the cable wire harness design is always according to the application's structure. A Cable wire harness is used in a lot of gadgets and machines. The following industries involve heavy use of wire harnesses in their products

• The automotive industry utilizes wire harnesses in car's electrical system
• The medical industry involves the use of wire harnesses in medical gadgets
• The defense industry makes use of wire harnesses in aircraft and defense technology
• The electronics industry heavily uses wire assembly in mobile phones and other electronic accessories.

A cable wire harness involves the use of multiple components like;

• Wires and Cables: These are the main components designed to distribute electrical signals within a device or application
• Terminals: Metal components that are attached to the end of the wires that enable wires to be attached to connector housings
• Connector housings: They are mainly mini plastic boxes that make a connection between wires secure and prevent it from loosening
• Cable straps or lacing: These are utilized to bundle the wires together in a cable harness.

RELATED: Difference Between Cable Harness And Wire Harness

Neglect Following the Assembly Diagram

An assembly diagram is a carefully designed circuit diagram that is drawn keeping in mind the specifications of the device or application. It is a blueprint of the entire cable wire harness. Applying hacks in connecting wires that do not match the pre-planned assembly diagram is a risky process that engineers should avoid. It can backfire and destroy the cable assembly, as a slight connection mistake can start a fire. In making and cable harness assembly going by the book is preferable, and strictly following the diagram is the way to success.

Incorrect Wire Selection

Inexperienced engineers usually make this mistake, as choosing a high-quality wire is the primary and foremost issue that should be kept in mind so that there are no faulty connections for the wire harness to function correctly. Wires having ends that are stripped improperly and have been cut carelessly are low-quality wires that run the dangers of weak connections.

Improper Crimping

Crimping means terminating the wires in a cable wire harness. Whether the wire harness is used in a giant machine like a car or a small gadget, the crimping should be done with extreme accuracy, and all the wires should be terminated foolproof. Careless crimping would result in short-circuiting that can lead to fire or explosion. All wires should be terminated with utmost care and attention to detail to prevent such dire consequences.

Careless and Messy Soldering

It is another error that can undermine the functionality of a cable wire harness. Many manufacturers or engineers engage in neglect and wire soldering. Incorrect soldering causes wires to heat up, leading to wire damage over the long term. Making use of the proper soldering equipment can prevent this error.

Using Wrong and Inferior Hardware

Manufacturing industries are fast-paced with tight project deadlines. To save time and make execution quicker, careless engineers take shortcuts and overlook crucial wires that are vital for making the wiring harness successful, and this ultimately makes the whole wire harness useless and non-functional. In addition, many manufacturers use low-quality components like screws, clamps, and cable straps. It would result in loose bounding of wires which would mean that the cable harness would not last long over the years and would start to unravel.

Faulty Wire Tying

Once the wire harness assembly is completed, the final step is tying wires using plastic tie wraps. Too much tightening of tie wraps can damage the wires, and a loose wrapping means that wire bundles will open up and wire will get spread out, which may loosen connections. Manufacturers should consider the wire-tying process to ensure the correct tension is applied to tighten wires.

Frequently Asked Question

How do you find a short in a wiring harness?

Finding a short in a wiring harness can be a challenging task, but here are some steps you can follow to help locate and identify the short;

• Visual Inspection.
• Closely inspect the cable wire harness for signs of damage.
• Check for fuses blowing. If a short circuit is causing a fuse to blow again and again then the location of the problem is near it.
• Make use of a multimeter to check resistance between positive and negative terminals.
• Perform the wiggle test which involves wiggling the wire while observing the multimeter.
• Use a short finder tool to trace the short by running a current and detecting magnetic field generated by the shorted wire.

What causes a wiring harness to fail?

Physical Damage: Any sort of cut, scratch or crushing of wire

Excessive Thermal Stress: Melting of wire insulation due to engine temperature can lead to short circuiting.

Corrosion: Moisture can seep into the wire and damage it.

Vibration and Shocks: Repeated shocks can loosen the connectors and cause electrical short-circuiting.

Incorrect Repairs: Faulty and error proof installation of wires after repair can lead to damage overtime.

How do you know if a wire harness is bad?

A bad wire harness can cause various electrical issues in a system, and there are several signs that can indicate a problem with the harness. Here are some common symptoms that might indicate a bad wire harness:

1. Electrical Malfunctions: If you experience frequent electrical malfunctions, such as lights flickering, intermittent power loss, or non-functioning electrical components, it could be due to a faulty wire harness.
2. Blown Fuses: If certain fuses keep blowing repeatedly, it may indicate a short circuit or overload in the wiring harness.
3. Burning Smell:A burning smell, especially near the wiring or electrical components, could be a sign of overheating due to a short circuit or electrical issue in the harness.
4. Visible Damage: Inspect the wiring harness for any visible signs of damage, such as frayed wires, melted insulation, or exposed metal. Damaged wires are a clear indication of a problem.

If you notice any of these signs, it's essential to inspect the wiring harness thoroughly or have it checked by a qualified mechanic or electrician. Diagnosing and repairing a faulty wire harness should be done with caution and expertise to avoid further damage and ensure the safety and reliability of the electrical system.

What is the easiest way to find a short in a wire?

The easiest way to find a short in a wire is by using a test light or a digital multimeter with a continuity (or beep) mode.