Wire Harness & Cable Design
The wiring between boards, engineered: connectors, gauges, lengths, and drawings a harness shop can build from without guesswork.
What is wire harness design?
Wire harness design is the engineering of the cables and connectors that carry power and signals through a product: circuit-by-circuit wiring definition, connector and wire selection, routing, and the build drawings an assembly shop works from. We design harnesses as part of the product's electrical system, with the same rigor as the boards they connect.
The last system designed, the first to cause trouble
In most projects the harness is improvised: whatever wire is on the shelf, whatever connector fits, routed however it reaches. The prototype works, the design ships, and the improvisation becomes a production part that no two builds make the same way.
Harness engineering replaces that with intent. Every circuit has a defined wire, every connector a managed pinout, every bundle a route chosen on purpose. The payoff arrives at integration, when boards connect correctly the first time, and again in production, when the tenth harness matches the first.
Documented so a shop can just build it
Harness shops quote against uncertainty. A sketch with missing lengths and vague terminations gets priced with padding for every question, then built with assumptions where the padding was not enough.
Our deliverable is the unglamorous package that leaves nothing open: from-to lists a first-year assembler can follow, drawings with every dimension called out, and termination details settled on paper. Shops quote it tighter, build it right, and your first articles stop being a negotiation.
Wire harness vs. cable assembly: which do you need?
The two terms get used interchangeably and quoted very differently. A cable assembly is one cable with terminations; a wire harness is a branched bundle that distributes power and signals through a whole product. Knowing which you need changes who can build it and what documentation they expect.
| Cable assembly | Wire harness | |
|---|---|---|
| What it is | A single cable, or a few conductors, terminated at each end | A branched bundle of many circuits, breakouts, and terminations |
| Typical role | Connecting two things: board to panel, device to host | Distributing power and signals through a product or machine |
| Documentation needed | A drawing with length, connectors, and pinout | Wiring schematics, from-to lists, and a dimensioned build drawing |
| Design effort | Modest: connector choice, gauge, and shielding | System-level: routing, bundling, EMC separation, serviceability |
Harness engineering we provide
From connection map to built harness
- 01
System Wiring Map
Every connection in the product gets captured: board to board, panel to power, sensor to controller. The map exposes the pin conflicts and missing returns before they become rework.
- 02
Connector & Wire Engineering
Connector families are chosen for keying, current, and mating cycles; wire gauges are derated for bundling and ambient temperature.
- 03
Routing & Protection
Lengths, bend radii, chafe points, and separation between noisy and sensitive bundles are defined while the mechanical design can still accommodate them.
- 04
Build Documentation
The output is a package a harness shop can quote and build without a phone call: schematics, from-to lists, and drawings with every length and termination dimensioned.
The drawing package
Harness capability at a glance
Wire Harness Design FAQs
Yes. We take the as-built harness (or the machine it lives in), trace every circuit, and produce proper wiring schematics, from-to lists, and dimensioned build drawings. Prototype wiring that lives in one technician's head becomes something any shop can quote and build.
When we manufacture your product, harness fabrication is quoted with the rest of the build. For design-only engagements you receive documentation complete enough for any competent harness shop, and we stay available for their engineering questions and first-article review.
Mostly by separation and discipline before any shielding is added. Power, signal, and sensitive analog circuits are assigned to separate bundles with defined spacing; twisted pairs handle differential and noisy runs; shields are terminated deliberately rather than by habit. Shielded cable solves the problems that layout and separation cannot, not the ones they should have prevented.
From the electrical load, not a chart lookup alone: continuous and peak current, allowable voltage drop over the run length, derating for wires bundled together, ambient temperature, and the insulation rating. The result is documented on the drawing so the harness can be built and inspected against it.
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