Considerations When Drawing a Wire Harness

The designing and drawing of a wiring harness are the basics of the entire process. Any slight mistake here can greatly affect the production and effectiveness of the final product. Here are a few guidelines to guide you through the drawing process to eliminate such a scenario. This will help you identify the available wire harness drawing options and develop solutions that align precisely with the project’s needs.

Drawing Wire Harness

Environmental Considerations

The cable harness drawing and design highly depend on several factors. However, one of the biggest determining factors is the environment in which the harness will be applied. Some will be subjected to extreme temperatures, water, chemicals, and oils. Similarly, the wire harness must feature flexibility to withstand vibrations abrasion.

The selection of the right wire type is critical in the drawing process. A simple mistake like the wrong wire selection can easily lead to insulation breakdowns. This can also lead to safety concerns and failure to abide by the wire harness drawing standards regulatory compliance like CSA, UL, and CE.

Parts Considerations

A perfect harness drawing has to include the right wire harness parts. If you choose to use your unique part number when drawing, make sure you can interpret this to your partner for better cross-reference with the manufacturer’s part numbers. If a certain part does not necessarily need a specific brand, it’s imperative to note “or equivalent” on the drawing part list. Doing so helps the contract manufacturer practically substitute the part with others that can enhance the wiring harness’s delivery, quality, and cost.

Drawing Wire Harness

Tolerance and Lengths

The harness drawing has to be very clear on the dimensions and tolerance. Here you can choose to measure starting from the front or rear.


Here you have several options, including split sleeve, braided loom tape, and conduit. All of them have different functions, disadvantages, and advantages. Ensure you get to understand each before you can determine which one should go into the cable harness drawing. Also, keep in mind not all parts of the wire harness will need covering.

Terminals, seals, and Connectors

The current market is full of different connectors types, seals, and terminals. It’s therefore easy to find connectors that accommodate the seals’ features, including wire gauge, terminal plating, or wire insulation thickness.

cable harness drawing

Important to note in your harness drawing, is that some connectors may need additional parts for perfect terminal locking.


When drawing the wire harness design, the connectors have to be easily identified through labeling. To achieve this, you should feature a note on the drawing. You can also include the harness specification part on the note.


Trying to get an exact balance of information on the cable harness drawing is next to impossible. Too many details and your drawing become cluttered, prone to errors, hard to interpret, and a nightmare to maintain.

Too little information, on the other hand, makes the harness drawing raise lots of questions or inconsistent final products. To eliminate such a problem, it’s important to work with your contracted manufacturer closely. Such a move will help you identify any markup on your drawing and develop better ways of revising the issues to offer a better solution.

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