Wire Harness Troubleshooting 345

adhesive

A chemical substance used to bond two objects together. Adhesives are found in some splice connectors.

aerospace

The industry concerned with the research, design, manufacture, and operation of air and space craft. Aerospace products include airplanes, helicopters, rockets, missiles, satellites, space capsules, space planes, and related systems.

amperage

A measurement of the amount of current flowing in a circuit. Amperage is measured in amperes (A).

automated test equipment

ATE. A device that performs tests on electronic components and systems to determine measurements and diagnose faults. Automated test equipment for wire harnesses may test the insulation and resistance and for proper connections between wires, terminals, and connectors.

brittle

A material that has limited resistance to being stretched, formed, or drawn. Wire harnesses can become brittle due to environmental factors and cause breakage.

butt-splice connector

A tube-shaped device used to connect two or more conductors and is secured by crimping both ends. Butt-splice connectors are used to repair damaged wires.

cable

A single large conductor or bundle of smaller wires insulated in a jacket. Cables allow electricity to travel from its source to its destination.

circuit breaker

A safety device that automatically opens a switch when it detects overcurrent in a circuit. A circuit breaker often contains a bimetallic strip that bends and trips a switch to open the circuit.

communication modules

A unit that exchanges data between nodes. Communication modules may work improperly if wire harness issues are present.

conductor

A material or element that allows free movement of electrons and therefore allows easy flow of electricity. Conductors are typically metals, such as gold, silver, copper, or aluminum.

connector

The part of a wire harness that plugs into a port in an electronic device. Connectors come in different varieties depending on the purpose of a wire harness.

contamination

The presence of unwanted materials or substances, such as dust or water, that can potentially damage or obstruct machine components. Contamination in wire harnesses can cause incomplete or loose connections.

continuity

The state of having a complete path that allows the uninterrupted flow of electricity. Continuity can be disrupted by manufacturing defects in wire harnesses.

continuity tester

A simple device used for testing electrical continuity. Continuity testers connect to a component with a probe and/or clip and will light up if continuity exists.

corrode

The gradual deterioration or wearing away of a material. Corrosion occurs in wire harnesses when exposed to sunlight, water, oil, or chemicals.

crimped

Pinched, bent, or pressed into the desired shape. Wires are crimped together during wire harness assembly.

de-energize

To remove all stored energy in a system. De-energizing a system eliminates the risk of electric shock.

diagnostic

A set of computer instructions that helps users or technicians investigate or analyze the cause or nature of errors or failures. Diagnostics performed by a wire harness tester can help identify the cause of problems in wire harnesses.

digital multimeter

DMM. A device that can measure voltage, amperage, and resistance. A digital multimeter can help diagnose electrical faults.

display sensors

A device that detects a change in a physical stimulus and converts it into a signal that is shown on a readout. Display sensors may behave unpredictably if a wire harness is damaged.

DMM

Digital multimeter. A device that can measure voltage, amperage, and resistance. A DMM can help diagnose electrical faults.

electric vehicles

EVs. A vehicle that uses full or partial electric motor power to propel itself forward. Electric vehicles use more wire harnesses than internal combustion engine vehicles.

electrical faults

Any condition that causes an abnormal flow of current in a circuit. Common types of electrical faults include open circuit faults and short circuit faults.

electrical fire

A fire involving energized electrical equipment. Electrical fires are very dangerous because they put employees at risk of electric shock in addition to burns.

electrical tape

A stretchy plastic tape that acts as an electrical insulator. Electrical tape should not be used to repair damaged wire insulation.

electrical testing

The process of evaluating circuits to ensure proper functioning. Electrical testing helps to ensure safety and diagnose wire harness issues.

electromagnetic compatibility testing

A simulation software that tests the tolerance of electromagnetic interference for wire harnesses in their environment. Electromagnetic compatibility testing helps to preserve signal integrity.

electromagnetic interference

EMI. Electrical noise that can interrupt or degrade the performance of a circuit. Electromagnetic interference can prevent wire harnesses from functioning properly.

EMI

Electromagnetic interference. Electrical noise that can interrupt or degrade the performance of a circuit. EMI can prevent wire harnesses from functioning properly.

environmental damage

Deterioration caused by exposure to environmental factors. Environmental damage can be caused by ultraviolet rays, temperature, or moisture.

error code

An alphanumeric message that references a specific cause of malfunctioning. Error codes for certain devices can indicate wire harness malfunction.

fraying

The unraveling of wire fibers caused by friction, prolonged use, or damage. Fraying wire harnesses can be caused by different types of damage.

friction

A force that resists motion between components that are in contact. Friction can wear down wire harnesses in heavy industrial machinery and cars.

hardware

Any physical or mechanical component. Hardware functions are controlled by software.

heat gun

A tool with a long body, handle, and trigger that emits hot air. Heat guns are used to shrink heat-shrink tubing when repairing wire harnesses.

heat-shrink solder splice connector

A tube-shaped device with solder in the middle that melts and contracts around a wire when heat is applied. Heat-shrink solder splice connections provide a water-tight seal.

heat-shrink tubing

A jacket of insulating material that decreases in size when heat is applied to it. Heat-shrink tubing is used to repair wire and cable insulation.

insulation

A material that does not conduct electricity. Insulation is applied to conductors like wires to prevent the unintentional flow of electricity.

internal combustion engine

ICE. A type of engine in which heat energy and mechanical energy are produced inside the engine. Internal combustion engines include gas turbines and types of diesel motors.

jacket

A protective outer layer of insulation on a cable. The jacket helps protect the wires inside the cable from environmental and mechanical damage.

lockout/tagout

A method of protecting employees by preventing accidental machine startup through proper locking and labeling of machines undergoing maintenance. Lockout/tagout is the common term for OSHA's Control of Hazardous Energy Standard.

manufacturing defects

An imperfection in a part or product that occurs during the production process and prevents it from operating correctly. Manufacturing defects in wire harnesses can cause poor connections or complete disconnection.

mechanical damage

Physical deterioration caused by mechanical forces. Mechanical damage may be caused by vibration or pressure.

misalignment

The incorrectly positioned or clipped wires within a wire harness. Misalignment of wires in a wire harness lead to entanglement, increasing the risk of open circuits and short circuits.

miswiring

The incorrect connection of wires to their terminals or components. Miswiring can lead to open or short circuits.

ohm

Ω. A unit of measurement for electrical resistance. The amount of ohms in a circuit can indicate whether an electrical fault exists.

open circuit faults

A type of electrical fault that prevents current from flowing through a circuit. Open circuit faults are often caused by broken circuit components such as wires or switches.

open loop

OL. A digital multimeter reading that indicates a lack of continuity in a circuit. Open loop readings indicate an open circuit fault.

overloading

The condition in which current flowing through a device or circuit exceeds the recommended level. Overloading can result from a faulty wire harness.

overshrinking

Causing a heat-shrink solder splice connector to decrease in size so much that it breaks the seal. Overshrinking can happen if too much heat is applied or heat is applied for too long.

performance degradation

The deterioration or breakdown of a machine's capabilities or quality. Performance degradation can signify a potential issue with a wire harness.

power drain

The loss or depletion of electrical energy in a device or system. Power drain can result from a faulty wire harness.

probe

A device attached to an electrical testing instrument that uses a conductive tip to connect to an electrical component. Probes connect to conductors and terminals.

resistance

The opposition to current flow. Resistance is measured in ohms (Ω).

robots

A machine that automatically performs complicated and repetitive tasks. Robots use wire harnesses.

root cause

The true origin of a problem. Troubleshooting attempts to identify the root cause of a problem rather than simply addressing the symptoms.

service manuals

A guide that gives instructions for maintenance, troubleshooting, and repair of a product. Service manuals can help with troubleshooting a wire harness.

shielding

A protective layer in an electrical cable that protects the wires within from electromagnetic interference. Shielding can be made from foil tape, foil wrap, or other metal materials.

short circuit fault

A type of electrical fault that causes current to flow along an unintended path. Short circuit faults can occur from exposed conductors in a wire harness.

signal degradation

The loss of quality or strength of a signal as it travels to the receiver. Signal degradation can result from a faulty wire harness.

simulations

A computer re-creation of a physical space, activity, or device. Simulations can help diagnose problems without physical testing.

software

A set of coded instructions or programs that control computer hardware functions and operations. Software is often used in conjunction with hardware.

solar panels

A device that converts light energy into direct current electricity. Solar panels use wire harnesses to help with the delivery of electricity.

solder

A metal alloy that has a low melting point and is used to join metals. Solder is essential to repairing wire harnesses.

soldered

Base metals that have been joined together with a filler metal. Terminals are soldered onto wires in a wire harness.

soldering iron

A tool used for precise applications that transfers heat onto a metal surface and melts solder. Soldering irons transfer heat through conduction.

splice connector

A tubular device that comes in many forms to join two or more conductors together. Splice connectors may require crimping, soldering, or the use of a heat gun.

split-half method

A troubleshooting technique that involves repeatedly dividing a malfunctioning circuit into two separate sections in order to narrow down the source of a fault. The split-half method, also known as the half-split method, is much more efficient than testing each part of a circuit individually.

strain

The physical deformation that occurs in an object when it is under stress. Strain in wire harnesses can lead to exposed or broken conductors.

system instability

The condition in which a system or machine behaves unpredictably or is difficult to control. System instability can signify a potential issue with a wire harness.

telecommunications

The industry that produces technology for the purpose of communication. Telecommunications equipment uses wire harnesses for transmitting communication signals.

terminal

A conductive component used to connect conductors between electronic devices. Terminals are crimped or soldered on to the ends of wires in a wire harness.

terminal deformation

The incorrect shape of the conductive component that connects conductors between electronic devices. Terminal deformation results from damage or manufacturing defects.

troubleshooting

A systematic elimination to determine the malfunctioning component in a system, circuit, or process. Troubleshooting a wire harness often involves using electrical diagrams to help determine the problem area.

ultraviolet

UV. A potentially harmful wavelength of light that is below, or shorter than, violet on the light spectrum. Ultraviolet rays can degrade the insulation of wire harnesses.

ultraviolet resistant cables

A type of cable designed to withstand ultraviolet rays. Ultraviolet resistant cables extend the lifespan of outdoor wire harness cables.

utility knife

A sharp, retractable blade designed to cut malleable materials. Utility knives are used to cut open the jacket of a wire harness.

visual inspection

A visual assessment of surface defects caused by manufacturing defects, mechanical damage, or environmental damage. Visual inspection of wire harnesses may require cutting open the wire harness jacket.

water-wicking

The absorption of water or moisture into a wire harness. Water-wicking can cause serious corrosion of wires.

wire gauge

A standard measurement used to describe the diameter of wire. Wire gauge affects a wire's resistance.

wire harness

A collection of wires organized and bundled according to function. A wire harness facilitates easy installation and saves space.

wire harness tester

A device that tests multiple conductors at once to identify safety and mechanical issues in wire harnesses. Wire harness testers check for open and short circuits, exposed wires, and proper connections between wires, terminals, and connectors.

wire nuts

A plastic device with an internal metal screw that digs into wires to join them. Wire nuts are not safe for repairing wire harnesses because they leave wires exposed to the environment.

wire stripping

The removal of electrical insulation from wires. Wire stripping uses a tool with notched blades designed to cut through insulation while leaving wires intact.

wires

A thin, flexible, elongated piece of metal. Wires usually consist of a metal conductor and a covering of insulation.

wiring diagram

An electrical print that shows the physical locations and electrical relationships of all electrical components in a circuit. Wiring diagrams can help with determining if a wire harness is properly assembled.