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Custom Wire Harness Manufacturer Supplier The Search

Custom Wire Harness Manufacturer

As a custom wire harness manufacturer C-T wireprep meets with many individuals over each year who usually is employed as purchasing agents or buyers for various OEM’s . Many of these individuals have a limited knowledge of the basics about what they are attempting to purchase or find a regular supplier for their custom wire harness or custom cable assemblies. This informative article was put together just for the sole purpose of helping out these individuals in their task.

So there you are in your purchasing job now finding it necessary to find a decent manufacturer who can supply you with custom wiring harnesses or cable assemblies. The reasons why you are searching could be many. From quality issues, cost reduction, or maybe a new product is coming on board and this is all new to you. Just keep on reading and we’ll get you up to speed on what you should look for and the questions to ask potential suppliers.

Prepare to search:

One of the very common things I notice when a purchasing agent contacts C-T Wire Prep is the necessary drawings and or documentation to be able to quote a custom harness are either outdated or non-existent. This can slow down the quotation process due to so many little but necessary questions that have to be answered. Now as long as you are not in a hurry this might not be a large problem. As an engineer I am able to visit your factory and see what requirements you may have and even build up a first off harness. This is usually done on a brand new product. For existing products drawings should be established and up to date. Check with your engineering department to make sure you have what is needed. For larger companies this will likely mean well drawn fairly complicated renderings that look like Greek to an average purchasing agent. For smaller organisations I’ve seen hand drawn renderings that work just find. This is usually because there is no engineering department and the purchaser is likely the owner of the company. A true example of one of our present customers is a utility trailer manufacturer. The company is owned by a pair of partners and they build about 4 or 5 hundred trailers per year out of a 10,000 sq ft. factory. One partner is the purchaser and looks after the office area for the most part, while the other partner looks after the production side of things. When I initially met with these fellows they simply handed me a harness and said “please quote this”. As long as the harness isn’t too complicated that is a simple and typical way it happens many times. At C-T we usually do create a drawing for our own internal use and build a first off custom wire harness from the original one supplied. We get it approved and keep it at our factory for reference each time we do a build.

So to summarize, if you do have drawings be prepared and get them because that is one of the first questions you will be asked. If you don’t, a working sample is the next best thing. The absolute best is both drawings and sample if possible.

Understanding wire processing and building of a custom wire harness or cable assembly.

A basic understanding of just how a manufacturer builds the harness or cable you need is something that helps you as a purchaser, so we will delve into the terms that wire harness guys throw around. We will also explain good manufacturing techniques that should be employed by all decent wire harness manufacturers.

First term that I get asked that seems to confuse purchasers is “What’s the difference between a custom wire harness and a custom cable assembly?” Well not much really other than the wire harness usually has several breakouts while a cable assembly is kind of like an extension cord you’d buy at your local hardware store. Cable assemblies usually just have two ends or breakouts to plug into. So look at your requirements and decide what to call it based on the above definition.

No matter which type of harness or cable you are seeking both will require at the least blunt cutting to length a cable or wire. Usually there is more to it and likely stripping of wire or jackets of cables as well as stripping internal wires inside a cable is necessary to prepare the assembly for the crimping of terminals onto the stripped ends of the wires.

Cutting Stripping, crimping Requirements:

Depending on how many harnesses or cables you require the method of cutting/stripping could vary. Tools such as hand plier’s side cutters might be used for low volumes or higher volumes usually employ a wire processing machine of some type. Typical names you will hear thrown around are Artos, Amp/Tyco, Eubanks, Schleuniger, komax, carpenter, megomat, as well as many others but those ones are the main machines used by most reputable wire harness manufacturing companies.

But just because they have good machines doesn’t necessarily mean they create quality. A good quality plan should be in place to prevent mistakes from happening.   Checks and double checks should be set up throughout the manufacturing sequence to ensure quality.

I’ll go through the checks we do at C-T that we use on our shop traveller sheet which follows the work through our production process. Each step an operator signs for the process they set up and or processed

  1. Our operators set up a machine for length of cut, they sign our shop traveller. Before the operator can go ahead with the cut, he or she must have the set up double checked and signed off on the shop traveller as well.
  2. On the shop traveller there are check boxes to check for correct wire being used, length of cut, stripped ends specified and their length. As well a few wires get cut and checked that the machine set up is not nicking out any copper strands. This is very important for ensuring your wire harness can handle the current it was designed to do. I can’t stress enough that a good quality plan will have a check and double check to guarantee the copper strands are all there and not damaged
  3. If there are any contacts or crimp terminals to be put on the shop traveller specifies which ones and on what end they are required. Also there is yet another sign off spot for any presses needing to be set up to do the crimping as well as an operator showing who actually did the crimping. A set up operator doesn’t necessarily do the crimping but must ensure the press is properly set up with the correct crimping die. This is confirmed by doing a destructive pull test.Again I can’t stress enough the importance of doing a pull test. Many wire processors will state they do a measurement of the crimp height rather than pull test. This is not good if you want quality. Pull testing a crimped wire is the only true measure of a good crimp.
  4. The pull test results are collected as data on the shop traveller to create a traceable history.
  5. If there is more processing to be done such as taking this wire that has been cut, stripped, and crimped and grouping it with other wires to build a custom wire harness, and this is where the drawings come into play. The drawings usually get put together with a kit bin of parts needed to build the entire product. Wires get processed each having their own shop traveller identifying them as to what they are part of. They get put into the kit bin. The drawing is referenced to identify the harness and a production procedure is developed to build the harness. If it is a complicated harness with many breakouts (connectors) there will usually be a harness build board developed to build the harness on as well as test it to make sure all connections are correct. A cable assembly may not need a build board but certainly must be put through a test to ensure all connections are correct and in place. Again I can’t stress enough this test must be done. Any company that suggests otherwise is not worth your efforts. They may come in with a lower price but I guarantee you will have issues with quality.
  6. The first harness built should be checked over for correct build including ties placed properly and all connectors properly housed.Other considerationsFinally one of the things sometimes overlooked by purchasers is just how the harness or cable assembly will arrive at your factory. Harnesses can quickly turn into a rats nest with breakouts all tangled creating lost time for your employee’s. Harnesses should be separately packed in plastic bags and if appropriate bulk packed in boxes depending on their size. Another consideration that should be addressed if you have more than one type of custom harness assembly or custom cable assembly is identification. Imagine having a pile of boxes that wind up opened up and 3 or 4 generations or types of harnesses all mixed up.
  7. Summarizing this article (what a purchasing agent should look for in choosing a custom wire harness company.
  8. Best to have some type of part number and revision level marked on the harness. Alternately at least a part number and rev level on the plastic bag that separates them.


  1. Make sure whoever you deal with addresses the checks and double checks. Have them show you a typical shop traveller sheet to verify.
  2. Make sure they utilize pull tests for every set up to guarantee a proper crimp. All crimps should be visually inspected before being inserted into the connectors.
  3. Make sure that all harnesses or cable assemblies are tested for correct placement and that they conduct properly. This is usually done with a harness test device.
  4. Of course there are many other aspects of quality to check out for various suppliers such as workmanship and having a good quality system in place. Concerning the wire processing industry the 3 main criteria have been addressed here in this article.

I hope you’ve found this article informative and useful to your needs with choosing a quality custom wiring harness supplier.

If you have any questions or want to check out C-T for your needs feel free to call or email us using the contact form above.

Thomas Collins Eng. Dept. C-T Wire Prep Inc.

Crimping Terminals Onto Cut And Stripped Wires

Achieving a quality crimp onto a stripped wire is always the desired result of any good wiring harness manufacturer.  The best way to achieve quality is to make sure first that the wire itself is stripped properly and not missing any strands of copper that might have been removed or damages by the stripping process.  another consideration is the length of the strip and even cutting of the wire sets up the correct situation for crimping properly.

Each different type of crimp terminal has a specified wire strip length that should be adhered to.  These specifications are usually found in the crimp terminal supplier catalogue either online or hard copy book.

Hand crimping is the least desired method of crimping as the number of variables is totally reliant on human skill and tact.

Press Crimping is the preferred method for limiting the variables to a reasonable level and eliminating most of the human error.

Presses must be set up by trained individuals who are well versed in crimp height measurement and knowing the manufacturer specifications for crimp height, as well as the CSA and UL pull test guidelines, which are confirmed for every set up by performing a pull test to verify the press crimping action.  Wire stops or feeds on automatic equipment must be set to the correct location to ensure no insulation will be crimped under the conductor crimp area.

Further to this it may be necessary for specialty crimping such as two wires under one crimp to be tested for millivolt drop measurement across the crimp area using a special test apparatus circuit evaluation.

The Crimping Press setup is paramount to achieve high quality crimps.

Crimped wires should be inspected carefully 3 different ways to verify the manufacturing process.

1.  Crimp height is measured and verified in spec to manufacturer recommendations

2. Pull test either performed as a destructive test or a pull and hold for a period of time (usually one minute) is performed to measure the force necessary to pull apart the crimp.
The non destructive hold for a minute test is just that, and then the crimped wire can be returned to the production run.

3. Visual inspection of the crimped wire should also be done by a trained press set up operator who knows what a properly crimped terminal should look like.  This is especially important for “F” type crimps.

Of course it goes without saying that measurements should be documented in some format and kept for reference by the wire harness manufacturing quality system.

At C-T Wire Prep Inc. we perform these press setups on a daily basis as we manufacture various wiring harnesses and cable assemblies.

Wiring Harness Manufacturing Quality Issues

Many business owners, engineers, production managers, and any other personnel, who are responsible for the quality and knowledge of their electrical or electronic wire processing, lack the information and training necessary to make sound decisions about quality issues concerning custom wire harness and cable assemblies.  When it comes This information lack is partly due to the fact that the knowledge, and information necessary to expose the issues involved in wire harness or cable assembly has typically been kept amongst a relatively few individuals. People who own, and or at one time or another worked for a cable assembly facility, that was exposed to a proper quality system, don’t let this information out freely.  There is a great deal of competition in the cable assembly and wire harness manufacturing industry, but at C-T we believe an informed customer is a good customer.

There is a large amount of information to go through to understand how to set up and control quality in a wire or cable facility.  Whether your cable wire fabrication shop is internal , and only part of a larger operation, or it is your main business focus, the need to set up a proper quality system is vital.  The cost of making a mistake is too large not to heed the recommendations of this article. 

At C-T Wire Prep Inc. the most valuable assets we have is our reputation and strong relationships with our customer base, and our well trained employees.   Training employees is vital to quality and following the methods that are described below are all part of a proper wiring harness quality system.

As you read through this article your will soon realize that the heart of quality in making wiring harness, cable assemblies, or even a simple lead assembly, relies heavily on good pull testing and a verification of repeatability program.  You will realize there is a good deal of testing involved in this field to maintain excellent quality.  As I go through the process of explaining the issues, I realize that not everyone will be familiar with the wire processing or cable assembly terminology, so I have added a glossary of terms page.  Keep in mind that there are always new processes and equipment coming along every year in the cable industry and this article is in no way considered finished.  Quality is always a work in process at C-T Wire Prep Inc. and therefore so is this document. I always encourage anyone who reads this article and wants to use it for teaching purposes, please feel free to do so.  All I ask is you return a link from your website with a remark as to where you got your information. 

Starting with the simplest operation in wire processing and build up to the most complicated manufacturing issues.  Lead assemblies are considered the simplest form of wire processing.  These will consist of wire cut to length, stripped, crimped or terminated on one or both ends with terminals or some other process.  Lead assemblies are considered the building blocks for wire harnesses.  Wire harnesses are lead assemblies added together in some fashion, and tied together becoming a wire harness.  Think of lead assemblies as having just two ends.  Wire harnesses have 3 or more ends running to various places (branches) making 3 or more connections.  Cable assemblies are a form of wire harness, but because of their nature have only two relatively distinct ends that run through the same jacket.  Most of the time the cable is brought in and processed in a different manner than wire harnesses. Cable assemblies can be made by creating lead assemblies of similar length, and fishing them through a loom or jacket, to produce the cable. Cable assemblies can also be made of extruded cable.  The ends are processed in a poke and strip manner, terminated and housed.  So to understand how to create an excellent quality model for wire harnesses, we need to understand the simplest item, which is the lead assembly.  In the making of a lead assembly there are several processes that can create a problem.  Wire type, wire length, wire colour, the length of the stripping of one or both ends, and what will be terminated on each end correctly, all must be considered.    Deeper than that are the real issues to obtaining excellent quality.  First do we have repeatability of the processes mentioned above and a true understanding of how to test a terminated wire properly is necessary.  So lets look at the repeatability process first.  This means understanding the options of how to build a wire lead assembly and which method is best suited. 
Crimping or terminating a wire with some kind of electrical or electronic contact can be done by hand (last resort), done on a semi-automatic foot pedal controlled press, or a fully automatic wire processing machine. 

First lets consider the hand tool.  Sometimes it is necessary to use a hand tool.  It is the least likely to give repeatability because it relies on operator skill, competence, and a quality attitude.  The operator is responsible to load the correct terminal, place the correct stripped end of wire into the proper place, all while holding the hand tool steady enough.  Once the operator feels sure they have the placement of terminal and wire correct they must squeeze the pliers handles together and create the crimp pressure to bottom out the hand tool so it will form terminal onto the wire.   
Benefits of hand tools: They are the cheapest method of tooling up.  They allow you to buy loose piece terminals and only what you need to do the job. 
Drawbacks of hand tools:  Repeatability is low for all critical criteria from terminal and wire placement to follow through on complete crimping action.  The operator will eventually become fatigued and run the risk of carpal tunnel, which could lead to a workman compensation claim.  Speed of operation is 100 – 200 crimps per hour.

Nest let’s consider the semi automatic press.  These machines were the next levels of developement in wire processing to eliminate the hand tool drawbacks.  The operator places the wire into a die, and when they feel it is properly situated, the activate the foot pedal to set the press in motion for one complete cycle of crimp.  These machines allow more control of the process because the die usually has a wire stop to aid in placement.  The terminals are also placed automatically by the die.  The press is set to the correct repeatable shut height, creating what is called terminal crimp height.  One extra item that can be added to these presses is some form of electronic crimp quality monitoring device.  (CQM) to catch mistakes as they happen in real time. 
Benefits of Presses:  Repeatability increases over that of hand tools substantially because the operator is responsible for less placement as well as not required to create the force necessary to crimp.   Speed of operator increases approx. 4 – 5 times that of hand tool rate.  Terminals are cheaper to buy per piece because of the minimum requirement of buying a spool at a time. 
Drawbacks of Presses:  Cost of press and associated tooling is substantially higher than a hand tool. Compared to a hand tool this method can range from 10 to 50 times more expensive.  You must buy terminals in larger quantities, usually on spools of 5000 pieces or more.  This may or may not be a problem depending on order quantity.  Training cycle to correctly set up a press of this type is a fairly long process. 

Now let’s look at the fully automatic wire processing machine.  This machine was developed to cut costs associated with processing wire, by combining the cut and strip  operation with the terminating operation for both sides of the wire all in a controlled cycle.  These machines usually are fed with wire from a barrel pack.  They have two presses similar to the semi automatic press above, that terminate both ends of cut to lenght and stripped wires.  Robotic feed arms control all placement and processing through the machine in a very repeatable fashion.
Benefits of automatic wire processing machines:  Repeatability when set up properly is extremely high.  Speed of operation is highest of all, approaching 3 – 4 thousand pieces per hour depending on length of wire cuts. Once the overhead of purchasing such a machine is out of the picture the cost associated with production is the lowest making for a competitive advantage.
Drawbacks of automatic wire processing machines:  Cost of the machine and associated tooling.  If the operator is not well trained a large volume of wire and terminals can be lost very quickly.  The training cycle for set up of this machine is a long process.

Obviously the more money you spend on the processing capability the higher level of quality you should achieve.  This only holds true if you have the rest of the necessary quality requirements in place that we will identify. 

Companies that have a low volume of wire to process are most likely to go the hand tool route, until they have a need for more wire processing.  Once that plateau is reached a decision has to be made as to whether or not to invest in semi automatic presses and dies, or farm out the work to a company like C-T Wire Prep Inc. If they have a mindset for quality it is really an easy decision to make.  As explained you aren’t likely to achieve the highest level of quality unless you purchase the most expensive equipment and train an operator properly.  Once the realization sets in that there is little to be gained unless you have a huge volume of wire to be processed, they may as well save their money and cut their overhead by finding a dedicated wire processor.  We have only touched on the 3 types of methods to process wire crimping, let alone involve the many other aspects of proper crimping methods and machinery to measure crimps.  The money a company could spend on setting up a good wire processing area would be more wisely spent of the promotion of their main business focus to gain market share.

Quality Wire Harness Manufacturing In Ontario Canada

Quality wire harness manufacturing doesn’t happen by accident, its a matter of long term experience building wire harnesses and knowing the intricacies of proper crimping methods, as well as having a wire harness quality system that addresses key areas. C-T Wire Prep has been building wiring harness for 20 years and has built up a reputation in the wiring harness industry as an authority. C-T has consulted and trained other wiring harness builders to perform various functions such as the proper way to dye wire, recommend wire harness testing techniques, even process wire and assemble harnesses as a sub contractor.

Engineering wiring harness is another service we excell at and help our customers save money by choosing widely used electrical connector systems that C-T already owns tooling for thus eliminating costly start up tooling costs. Our engineers steer you to the most cost effective connection systems that are also quality connectors.

Cable assemblies are sometimes also called wire harnesses. The only difference is cable assemblies usually just have two ends like an extension cord where as wiring harnesses have multiple branches heading off in many different directions. A wiring harness quality system must address each possibility in a custom way. C-T Wire Prep creates a custom cable assembly or custom wire harness quality plan for everything that is produced. This includes the sub assemblies right down to discrete wires.

When you need to obtain a wire harness quote C-T will require some information. Usually this information includes drawings with part numbers and descriptions of wire styles, gages, colors, lenghts, connectors and pin outs of connectors. If you require CSA wire harness or UL wire harness C-T is certified to produce both.

Please contact us directly through our contact page via email or by telephone at 519 448-1125 or fax 519 448-1109.