How to Get Started with Your OEM Wire Harness Project

Wire Harnesses Design

An Original Equipment Manufacturer (OEM) is able to produce the exact parts required to fit within a system per strict specifications. OEMs are most commonly recognized as the manufacturers for parts used within the automotive industry but are widely used through a myriad of different applications. Custom wire harnesses for OEM applications therefore have to be perfectly suited to meet the specific demands of the application. 

In today’s LiveWire feature, we’ll look at the wide world of OEM wire harnesses and how these vital workhorses go from concept to volume manufacturing on their way to power some of the most sophisticated automotive systems on the planet.

What is an OEM Wire Harness?

First off, a wire harness assembly is the collection of wires, cables, terminals and other components that are then insulated, sheathed, and otherwise protected to fit the needs of their environments. An OEM wire harness is one that is built to the exact specifications as the original part in order to fit within an existing system. If you think about an automotive application, you have so many different systems within the vehicle that all must remain powered, with free exchange of signal, power, and data in order for the vehicle to safely operate. 

Wire harnesses are an especially critical support element as an OEM part. OEM wire harnesses are going to provide the connection needed to relay power, data, and/or signal to all the outlying systems. The alternator, battery cables, headlights, and a hundred other systems in the vehicle all rely on wire harness assemblies to maintain the connection. Vehicles are subjected to a lot of environmental forces that all require mitigation. 

Finding efficient ways to protect against all of the variables bombarding a wire harness assembly, our engineers take many steps during the design and prototyping phases to ensure our custom OEM wire harness assemblies are performing exactly to spec.

Designing an OEM Wire Harness

An OEM wire harness’s design is absolutely critical towards its overall functionality within the larger system it is intended for. There’s both a physical space requirement component, as well as a certain threshold for the transmission of data, power, or signal that play into the overall design. There’s also the environmental factors we just mentioned that also need to be accounted for in order to produce a viable and effective product. 

  • Space Constraints With OEM Wire Harnesses: cables and wires have to traverse some pretty tight spaces in order to provide the critical junction between different components. Whether it’s for a multi-million dollar fighter jet or a piece of industrial control equipment powering a municipal waterworks, space constraints play a huge role in dictating final design. When a cable is bent, the wire harness engineer will have had to factor in this stress and provide the right materials and overall design that best meets these conditions. We’ll touch more on testing OEM wire harnesses a little later. 
  • Power, Signal, and/or Data Requirements: different cables from coax to CAT5 are utilized within electrical systems to provide the necessary functionality. With power needs, the gauge of the wire dictates how much current can safely be transmitted through the system. The size differences here within a cable require engineers to provide just the right amount and type for structural components such as insulation and filler materials. While these support elements can be easily forgotten when looking at the finished OEM wire harness, without them, the system would not remain operable for long. 
  • Mitigating Against External Factors: think about the underside of your vehicle traveling down the highway day after day. When you walk out first thing in the morning to power your vehicle, you’re pretty much counting on it to start right up and get you where you need to go. But this would be impossible if the OEM wire harness engineer for your vehicle’s electrical systems did not plan for environmental variables in their initial design. Oil and caustic agents, moisture, abrasion, heat, and others all require a keen set of deterrents that are effective both in the efficiency of design, as well as related to budget. Operating within budget keeps an OEM wire harness feasible for the final application. 

When you have considered all of these different constraints of a project, you can design a wire harness that fits within that framework The various wiring and cables all need to be easily-deployed within their application, which requires exacting specifications based on a present set of data. Our engineers work to solve even the most complex integration issues to ensure our harnesses provide a seamless “drop-in” installation. 

Bringing an OEM Wire Harness Assembly From Concept to Reality

When our wire harness engineers are producing designs for new OEM wire harnesses, they are running multiple iterations through sophisticated modeling software that let’s engineers see how a system will perform under a variety of simulations. The design that moves forward to the assembly of the wire harness is called a schematic which then gets translated into a physical assembly board, also referred to as a pin board.

A pin board is like a large diagram of an OEM wire harness which helps to map out all the different parts and pieces with their specific location to match the necessary applications set by the manufacturers specifications. Wires and cables have systems of identification, along with the proper terminals, connector housings, and other pieces to integrate the final harness assembly. 

All of these components have been placed perfectly within the system to maximize efficiency and utilization. Support structures such as cable sleeves, ties, and straps are all required to protect and strengthen the overall electrical system. The process to produce each of the various components takes a blend of fully-automated, semi-automated, and hand tools to produce the final product. 

While automation and semi-automation are utilized when it’s most efficient to do so, much of the work of an OEM wire harness assembly is still completed by hand because there are so many intricate processes. 

Testing is Everything with OEM Wire Harnesses

Even during the design and prototyping phases, testing is a constant part of the process. Testing during the design phase, helps to save time and money during prototyping, which in turn, saves time and money for the overall project timeline. Meeting each major project milestone on the project schedule takes careful planning from the start.

When looking to test electrical functionality with an OEM wire harness, a test board is a good place to start. A test board is one that comes programmed specifically to test the unique characteristics of that particular product. A wire harness is dropped into a test board much like it would need to plug and play with its final destination. The test board is just one of the many resources available within Meridian’s in-house Advanced Life Testing Lab. 

The Lab is arguably one of the funnest places at our facility as engineers put wire harnesses through a variety of extreme tests based on real life scenarios. Freezing and burning, bending and stretching, and even automated testing from our venerable Cirris testing units are in store for any OEM wire harness that wants to make it past quality assurance testing. Often, prototypes are used for testing before volume or even small-batch production to ensure the final iteration is the most efficient design possible. 

Bringing it All Together

Having the best design and manufacturing process in the world for OEM wire harnesses is meaningless if you can’t bring it all together to get to your customers what they need, when they need it. Having fully-owned manufacturing facilities in both the US and in China, allows our team to utilize a global logistics network to source materials, assemble designs, and deliver the product on-time and on-budget. This level of commitment is earned through many years of tweaking your processes in order to find the best mix for your unique offering. 

Meridian is proud to maintain our ISO 9001 certification which is only accomplished through a continued commitment to improving processes across the board. Formal quality assurance quality control (QAQC) procedures are put in place, as well as techniques like Kanban manufacturing and Just-in-time ordering to ensure efficiency of process. 

A crucial aspect of ISO 9001 quality management certification holders is that they also must commit to improving their service to the customer as well. We’ve learned over the years that honestly looking at each and every interaction with our clients and systematically reviewing how we could have done things better has allowed us to continue to deliver exceptional results for our clients.

Getting Started with Your OEM Wire Harness Project

At Meridian, we simply take the time to ensure that everything is done right. After decades of providing the OEM wire harnesses for some of the most sophisticated electrical systems on the planet, we have amassed both the tools and the talent to produce exactly what’s required. Contact our team now to start reviewing your project specs.