Wiring Harnesses – What Could Go Wrong?
April 12, 2012 at 3:01 PM
If you are connecting two points with more than a single wire, you’re constructing a wiring harness. Development of a high quality wiring harness isn’t rocket science, so why do so many harnesses have problems? TEK Services has made a business out of designing and manufacturing professional wire harnesses for our customers. In our experience, customers that try to do this on their own fall down in a number of areas. If you pay attention to the details, however, you can produce a wiring harness you will be proud to put in your finished product.
Select the proper materials:
Wire – Selection of the right wire for the job. This subject is too broad to cover in any detail here, but suffice it to say some of the factors that must be considered are: Flexibility requirements of the application, current carrying capacity, corrosion resistance of the conductors, expected voltage levels, and insulation characteristics.
Terminals – crimped, soldered, or specialty (military, marine, etc.)
Connections – soldered or non-soldered connections. Lead or lead-free. Crimping by hand, machine, or ultrasonically welded. Sealed or unsealed.
Heat Shrink, Expandable Mesh Sheathing or other covering.
Most wiring harnesses require a full scale template. The template must take into account the routing of the wire harness in the finished product, as well as the stiffness of the materials involved.
The most common errors during production include: cuts and nicks to the wire insulation, breaks in the wire strands, improper crimping of the terminals (leading to terminal pull-off, or cut-off), improper labeling, failure to stress relieve wire after application of solder, wicking of solder beneath the insulation and/or outer sheathing, and damage to the connection due to improperly applied heat shrink or mesh sheathing.
Harnesses should normally be tested for electrical continuity during or after assembly. This is often accomplished in higher volume jobs with a dedicated test set, but can also be done with a continuity checker. In some cases high voltage tests are also appropriate, depending on the end product for which the wire harness is intended. UL certification is also a requirement in some applications.
Contract Manufacturing of Wire Harnesses
Many customers find it more convenient, more cost effective, and more professional looking, to have a contract manufacturer produce their wiring harnesses. Contract manufacturers have the advantage of already possessing most of the specialized equipment necessary to automate production. In addition, customers benefit from greater buying power and the consistent application of quality standards (ISO 9001:2008, IPC 620), and production standards specific to wiring harnesses. In most cases we have found contract manufacturing of wiring harnesses to be a significant benefit to the customer, and a win for both companies.
TEK Services is a contract manufacturing company located in Eastern Nebraska specializing in metal working (laser machining, CNC, welding, laser cutting, metal cutting and other services), wiring work (wire end terminals, small wire terminals, wiring harnesses, circuit board assembly and other services), and electro-mechanical assembly. Our website is www.tekservices-mfg.com, and our phone number is 402-727-0262.