For a wiring harness to perform its function, every conductor, terminal, connector and protective component has to be correctly specified, processed, assembled and tested. For equipment operating in mining, construction, agriculture, automotive and other industrial applications, a harness failure can bring a machine to a halt.

This places the manufacturing of wiring harnesses within the engineering and production environments rather than simply being an assembly operation. Johannesburg-based Harntech has built its business around this principle, combining harness design and manufacture with auto electrical solutions, testing, reverse engineering, CNC machining, fiber laser cutting, sheet metal fabrication and electro-mechanical assembly.

Harntech has research, design, and development capabilities that are fully integrated into its drawing and design services and on-site consulting services

Established more than 20 years ago by Managing Director Ju-an Berlowitz, an auto electrician by trade who had specialised in the mining industry, Harntech operates from a 3 800m2 manufacturing facility in Longlake, Johannesburg, employing some 250 people. The company supplies wiring harnesses, cable assemblies and electrical and electro-mechanical solutions such as cabinetry and enclosures to the agricultural, alternative energy, automotive, commercial trucking, construction, electronics, marine, rail, military, mining, off-highway and transportation sectors, mainly for OEMs.

The scope of these markets has shaped Harntech’s manufacturing capability. Rather than concentrating on one harness configuration or production volume, the company manufactures everything from single lead wires to complete vehicle cab harness systems. Production can accommodate low, medium and high-volume requirements, while the engineering department supports customers from the initial design through to production.

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“After a few years of working for a company that was supplying harness equipment into the OEM mining market my wife and I decided to take a chance and start our own business. We did this initially out of my grandfather’s garage servicing some of the heavy-duty mining equipment like excavators and dump trucks. Slowly we started building up the business and employing more staff, training them up through their apprenticeships and growing our client base,” explained Berlowitz.

“We saw an opportunity specifically in the wire harness industry and decided we wanted to provide a full turnkey service here, and gradually we started to acquire more and more OEM customers. From there, we started to branch out into other industries like the agriculture, military and alternative energy sectors, and now we are able to serve almost any industry that requires a wiring harness.”

Harntech manufactures everything from single lead wires to complete vehicle cab harness systems

“More growth led to us receiving an enquiry about becoming a tier 2 wiring harness supplier into the automotive industry locally. This was a huge transformation period for us as a business as along with this opportunity came all the needed certifications to enter this industry.”

“Today the business essentially has two aspects to it – what we call the high-volume part of the business where production runs can be a little bit more predictable through forecasting, and then the low-volume job shopping type side of the business.”

From design to production
The manufacturing process starts before a wire is cut for Harntech. “Part of our offering also now includes a full turnkey service where we will go out to site to meet with a client, take measurements, 3D scan an application and come back to our factory to produce a prototype for the client before beginning production. This process involves using our CAD software like SolidWorks and Arcadia software systems.”

Production of harnesses can accommodate low, medium and high-volume requirements

“The Arcadia CAD suite is a specialised, complex electrical schematic design software, wiring harness layout and manufacturing aid. It uses proprietary AI-powered tools to automate tedious electrical tasks and monitors schematics to predict pin selections, automate circuit behaviours, analyse voltage drops, and generate real-time manufacturing instructions to eliminate human errors.”

Harntech can work from customer drawings or undertake the design of a harness for a particular function and harness designs produced can then be transferred into the company’s own manufacturing systems before production begins.

This provides a link between the engineering data and the production floor and allows the manufacturing process to be documented and repeated. Harntech has invested in automated wire-processing equipment capable of processing wire up to 25mm, while other equipment can handle cable sizes from 16mm to 240mm. Wire marking can be carried out using non-contact inkjet, hot-stamp and laser systems, as well as heat-shrinkable identification tubes.

Harntech supplies wiring harnesses, cable assemblies and various electrical and electro-mechanical solutions from OEM replacement wiring harnesses to plug and play installation kits

Other production capabilities include wire twisting up to 2.5mm and lengths of 5 000mm, automatic and semi-automatic terminal crimping and hydraulic crimping up to 150kN.

Crimping is a critical operation in harness manufacturing. An electrical connection can have the correct appearance and still contain a defect that affects its electrical or mechanical performance. Harntech therefore applies crimp-height verification, pull-force testing and crimp-force monitoring to its production process.

For battery and power cables, the company carries out dual-range pull-force testing up to 10 000N. The use of controlled hydraulic crimping, combined with inspection and test data, provides a means of monitoring the repeatability of the connection. Harntech also has ultrasonic wire-splicing capability for assemblies up to 35mm, with dual-wall adhesive covering available for additional protection. Harness protection includes PVC braided nylon-coated yarns, convoluted tubing, military-specification heat-shrink tubing and flexible and expandable braided sleeving.

Engineering for harsh environments
The operating environment is an important consideration in many of Harntech’s applications and mining and off-highway equipment exposes wiring to vibration, abrasion, moisture, contamination, temperature changes and mechanical damage. The harness therefore has to be designed as a mechanical assembly as well as an electrical one.

Part of Harntech’s sophisticated assembly and testing line

This is apparent in Harntech’s OEM replacement harness business and the company uses reverse engineering to reproduce harnesses for equipment where OEM parts may no longer be available, have extended lead times or carry high replacement costs.

The process can start with a sample harness, electronic drawings or other available engineering information. Harntech then recreates the assembly and incorporates changes intended to address known failure points.

One example of this approach is the addition of protective boots and connector backshells to designs where these were not included in the original harness. Protection against water, dirt ingress, abrasion, heat and mechanical damage can be incorporated according to the application.

Harntech recently invested in an Amada 3kW ORSUS-3015AJe fiber laser with a working area of 3m x 1.5m. Layout on the shop floor has been done in such a way that there is room to add Amada’s automation solutions to the system. All of Harntech’s new Amada equipment has been supplied by Amada Johannesburg

The objective is not simply to reproduce a part but to understand why a harness failed and determine whether the design, materials or protection can be changed to improve its service life, says Berlowitz.

Harntech also maintains an inventory of harness components and materials covering equipment from different manufacturers. This, together with its component and design database and use of interchangeable industry-proven components allows replacement harnesses to be produced without relying on the complete OEM supply chain.

Furthering its in-house manufacturing capabilities, Harntech have also invested in an Amada SRB-1003 100-ton press brake with 3m bending length, supplied by Amada Johannesburg

Manufacturing beyond the harness – Amada automation
An important part of Harntech’s capability is the extent to which manufacturing now extends beyond wire processing. “A problem we were encountering with the outsourcing of some of our steel work manufacturing was the lead times. Sometimes the design in the CAD work doesn’t always match up to the finished product and waiting four or five weeks to receive the material back only to realise something is misaligned or doesn’t fit as it should creates a bottleneck scenario for the rest of the production line. Even something like a little bit of powder coating can take something out by 1mm.” explains Berlowitz.

“Our customers are always looking for continuous improvements to their products and by being able to hierarchically control the manufacturing process in-house gives us the ability to be more innovative and engineer new solutions. This is not an easy industry and every operating environment – be it above or below surface, or even location-specific environments with harsh climates, bring their own challenges and unique set of operating requirements. This is where we have really had to learn how to engineer products that outlast those situations and challenges.”

Safely contained, Harntech’s new Amada FLW-1500MT handheld fiber laser welding machine

“To better this aspect of the manufacturing process, we’ve invested in an Amada 3kW ORSUS-3015AJe fiber laser with a working area of 3m x 1.5m, an Amada SRB-1003 100-ton press brake with 3m bending length and Amada’s FLW-1500MT handheld fiber laser welding machine. All three of these automation solutions have been supplied by Amada Johannesburg, and we’ve incorporated them into our production line in such a way that we have left room to further automate them, for example we can add a palletising or manipulator system to the ORSUS fiber laser.”

The machines are all fitted with Amada’s latest software packages that integrate backend design programming and smooth CAD file importation. Berlowitz says some of the intuitive features really add to the overall useability of the machines and optimisation of material nesting with the ORSUS for example helping to minimise scrap and maximise material yield. The digital twin capabilities incorporated into the Amada SRB-1003 press brake vastly help to eliminate operator error through simple but extremely useful features such as telling the operator which tools to select, and what the component should look like once bent up.

Harntech are generally processing material thicknesses in the 1.6mm to 2mm range but has processed material of 5mm in thickness and can manufacture a wiring harness up to 25m in length.

Harntech’s Amada’s FLW-1500MT handheld fiber laser welding machine, supplied by Amada Johannesburg

Beyond fiber laser cutting and engraving, sheet metal fabrication, using 3D printing for rapid prototyping for components such as brackets, clips, cable guides, covers and enclosures that can be produced for design validation or low-volume applications, reducing the need for dedicated tooling during development, these new automation capabilities allow components associated with electrical systems to be produced alongside the harness. These include such control panels, power distribution units and dash panels. Materials processed include aluminium, steel, plexiglass and engineered plastics.

Sheet metal work includes the production of enclosures, brackets, mounting plates, frames and other components.

Laser engraving is used for instrument-panel films, identification plates, decals, legends and serial-number plates. Instead of outsourcing every mechanical component associated with an electrical assembly, Harntech can manufacture a number of these components in-house and the combination of these processes is significant for low-volume and engineered products and the relevant associated quality control processes involved before products are delivered to customers.

The company also undertakes electro-mechanical assembly, bringing wiring harnesses, electrical components, control systems, housings and mechanical hardware together as completed units.

Harntech also manufacture rugged power distribution solutions resulting in reliable circuit protection and built for off-highway performance

Electrical systems for specialist vehicles
Harntech’s work in specialised vehicle applications demonstrates their turnkey approach to the wiring industry as a whole. The company supplies wiring harnesses and electrical systems for body builders and manufacturers producing water and diesel bowsers, service trucks and fire trucks. It also manufactures power distribution units, isolation and lockout stations, boarding-light controllers and lighting upgrade kits.

Electrical rebuild kits provide another route to simplifying assembly and these can combine harnesses, battery cables, lighting systems, dash panels, switches and associated electrical components into a single package.

Harntech supplies also connector repair kits containing the components required to carry out field repairs for onsite maintenance operations. The kits can be configured for particular OEM equipment and are intended to reduce the time spent identifying and sourcing individual connectors and terminals.

This method is also relevant to mining fleets, where the cost of equipment downtime can exceed the cost of the replacement electrical component.

Engineered for reliability in the harshest environments, Harntech’s Emergency Stop solution ensures immediate intervention, enhanced operator safety, and uncompromising performance for off-highway machinery

Testing and traceability
Manufacturing a harness is only part of the process. The finished assembly has to demonstrate that the electrical paths and insulation are correct. Harntech send completed wiring harnesses to computerised eTesting stations located along the production line for testing for continuity, short circuits and insulation breakdown, that is then followed by final manual inspection. Test results are electronically recorded and stored, providing production data and traceability.

The company also has testing capability for military-grade harnesses and cables using MK Test Systems equipment. This includes continuity and resistance measurement, high-voltage insulation resistance testing from 500VDC to 15kVDC, and Hipot testing from 500VAC to 8.5kVAC.

Connector testing includes four-wire Kelvin resistance measurement, low-voltage isolation testing, capacitance measurement and high-voltage insulation testing. Functional testing can be applied to relays, diodes, solenoids, sensors, actuators, contactors and lamps.

Lock Out. Tag Out. Stay Protected. Designed for the mining industry, Harntech’s Isolation and Lockout Station helps prevent accidental equipment energisation, keeping maintenance teams safe and operations compliant

IPC/WHMA-A-620 is the international consensus standard for the requirements and acceptance of cable and wire harness assemblies and provides a common basis for workmanship and inspection, for which Harntech is equipped.

Harntech manufactures under an ISO 9001 quality management system and its production processes incorporate IPC/WHMA-A-620C inspection requirements, while its internal training programmes are based on IPC/WHMA-A-620E. Harntech is also IATF 16949, ISO 14001 and ISO 45001 compliant.

Applying Kaizen to harness production
Continuous improvement has become part of Harntech’s production strategy and in 2025, the Department of Trade, Industry and Competition’s Quality and Productivity Improvement/Kaizen Awards recognised Harntech in the medium-size category. The company had adopted the Toyota Production System and its Kaizen approach under Berlowitz and one improvement involved combining assembly steps to reduce unnecessary movement of harnesses during production, resulting in significantly improved production time.

Before Harntech’s products are distributed they undergo rigorous testing. One of these processes ensures each harness is identically manufactured to its drawing

Reducing movement, improving workstation layout, standardising processes and monitoring production data all have an effect on harness manufacturing cost and output. Berlowitz and his team have put a great deal of effort into continuously improving this aspect of the business to ensure every operation is as streamlined and productive as it can be.

The breadth of Harntech’s operations means that the company occupies a position between a wiring-harness manufacturer, auto-electrical supplier and engineering business. For an OEM, the requirement may be a production harness manufactured to an existing drawing. For a mining customer, it may be a replacement harness that has been reverse engineered and modified to address a recurring failure. A specialist vehicle builder may require a complete electrical installation kit, while another customer may require a control panel, power distribution unit or electro-mechanical assembly, and this is where Harntech has engineered itself a niche in this market.

These different requirements have driven the development of an operation that covers the manufacturing process from concept to final assembly.

Harntech is capable of manufacturing wiring harnesses up to 25m in length

Supporting industrial equipment
While automotive applications remain an important part of the business, Harntech’s market reach reflects the increasing electrical content of industrial and mobile equipment.

Mining related equipment, construction equipment, agricultural machinery, commercial vehicles and specialised trucks all depend on electrical systems for starting, control, sensing, communication, safety and auxiliary functions. This is a common trend worldwide, and as equipment becomes more electronically controlled, the harness becomes a critical part of the apparatus architecture. It carries power and signals between sensors, controllers, actuators, displays and other electrical systems. Failures can therefore affect more than a single function.

Harntech’s owner and Managing Director, Ju-an Berlowitz. Berlowitz established Harntech 20 years ago out of his grandfather’s garage. The company now operates from a 3 800m2 manufacturing facility in Longlake, Johannesburg, employing some 250 people

Harntech’s manufacturing model is now based on controlling more of the processes in-house, combining engineering, manufacturing and testing at several levels and this also provides a means of competing on lead time, engineering support and the ability to adapt a product to a particular machine or operating environment. Harntech can manufacture up to 70 000 harnesses a month.

The wiring harness may be one of the less visible components within a vehicle or machine, but its role is fundamental.

For further information contact Harntech on Tel: +27 11 894 3339 or visit: https://harntech.co.za