Disclosure: This guide is published by Cloom Tech. Cloom Tech is one of the six companies listed below, and the decision block at the end is a sponsored, disclosed element that routes you to Cloom Tech.
Most modern vehicles carry many wire harnesses with thousands of wires and hundreds of connectors, so the supplier you pick affects prototype speed, quality documentation and how well the harness holds up in production. This guide does not rank suppliers. It sets out the questions to ask and gives the same facts for each company so you can compare them yourself.
What should I check before shortlisting an automotive wire harness supplier?
Use these criteria for every company in this guide:
- Quality system: which certifications the company publishes, and at which sites.
- Where the harness is built: the company’s own stated locations. Some suppliers list headquarters in one country and production in another.
- Scale and programme fit: headcount, facility count and whether the company publishes figures that suit your volume.
- Product scope: whether the company publishes automotive harness work, including high-voltage or electrified-vehicle work.
- Prototype-to-production path: whether the company says it supports both.
Figures below come from each company’s own website unless marked otherwise. Anything a company did not publish is left out, not estimated.
Which automotive wire harness manufacturers and suppliers serve US buyers?
The six companies are listed in alphabetical order. Order does not indicate quality or preference.
Aptiv PLC
- Founded / name history: Delphi Automotive became Aptiv PLC in 2017 (company timeline).
- Scale (company-stated): more than 51,000 people in 23 countries.
- Automotive focus: high-voltage interconnects and inlets, plus Smart Vehicle Architecture for electrified and software-defined vehicles. Its timeline lists the 2022-era acquisition of Intercable Automotive Solutions for high-voltage architecture.
- Certifications (company-stated): Aptiv’s corporate “About” and sustainability pages do not publish a company-wide certification list. Its Connection Systems (interconnect) division site publishes a facility-by-facility certifications index naming ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, AS9100D and ISO 13485:2016 at specific plants (for example, facilities labelled “RF & Microwave Facility” and “Cable Assembly Facility”). IATF 16949 is not listed on that index for the facilities shown.
Trade-offs:
- Strength: deep high-voltage and electrified-architecture scope.
- Limit: a large Tier 1 supplier, so confirm early whether it will quote small or prototype-only volumes for your programme. Its own certifications index (at the Connection Systems division level) does not show IATF 16949 for the facilities listed, so ask which standard the specific plant that would build your harness actually holds.
Cloom Tech (Hebei Cloom Electronic Technology Co., Ltd)
Cloom Tech is one of the six companies in this guide. Its facts below use the company’s confirmed reference data. Cloom Tech also manufactures custom cable assemblies alongside its automotive wire harness work.
- Founded: 2017.
- Facility size: 5,000 m².
- Locations: Shijiazhuang, Hebei, China (headquarters and plant); Cavite, Philippines (plant, near Manila); Medley, Florida, USA (office).
- Scale (company-stated): 1,000+ cumulative clients since 2017.
- Certifications (valid): ISO 9001; IATF 16949 (valid to August 2029); ISO 13485 (medical wire-harness production); IPC/WHMA-A-620E CIS (operator and inspector qualification).
- Automotive focus: custom OEM wire harnesses built to customer specifications.
Trade-offs:
- Strength: a valid IATF 16949 certificate and a stated 5,000 m² facility.
- Limit: Cloom Tech builds in China and the Philippines and has a US office, so confirm where your harness would be produced and what that means for lead time and cost. It does not supply off-the-shelf catalogue harnesses.
Lear Corporation
- Scale (company-stated): 164,300 employees globally, 258 facilities, 36 countries.
- Automotive focus: automotive seating and electrical systems (company “Company” page).
- Certifications (company-stated): not published as a company-wide list on Lear’s own corporate site as of this check — lear.com’s site map and Company/Suppliers pages have no quality or certifications page. Lear’s own supplier bulletin states that IATF 16949 and ISO 9001 certifications are required of Lear’s suppliers; it is a requirement Lear imposes, not a claim about Lear’s own facilities.
Trade-offs:
- Strength: very large footprint, suited to multi-region OEM programmes.
- Limit: scale-focused; confirm the plant that would build your harness and whether it accepts small runs. Lear’s own site does not state which of its facilities hold which quality certifications, so ask for the specific plant’s current certificate directly.
Motherson
- Founded: 1975 (company history page). Headquartered in India.
- Automotive focus: global automotive components, including wiring systems, through its joint venture history with Sumitomo Wiring Systems (company history page).
- Certifications (company-stated): Motherson Group does not publish a group-wide certifications list on motherson.com, but the company’s own site hosts third-party-issued IATF 16949 certificates for individual plants, e.g. Motherson DRSC Deutschland GmbH’s Tschirn site (Certificate 0522255, TÃœV SÃœD, issued 2024-06-10, valid to 2027-06-09) and Judenbach site (Certificate 0522588, TÃœV SÃœD, issued 2024-06-11, valid to 2027-06-10). Both are scoped to design and production of precision functional plastic components, not specifically wire-harness production.
Trade-offs:
- Strength: long track record and a global supply base.
- Limit: headquarters are overseas, so confirm which North American facility would build your harness. The certificates found on its own site cover specific German plastics-component plants, not a wire-harness-specific or North American site, so ask for the certificate that actually covers your build location.
Precision Cable Assemblies (PCA)
- Founded: not verified in this pass. Facilities listed on its site: Brookfield, Wisconsin (manufacturing), Waukesha, Wisconsin (warehousing and distribution), Guadalupe, Nuevo Leon, Mexico, and Qingdao, Shandong, China.
- Certifications (company-stated): ISO 9001:2015 for USA and Mexico sites; IATF 16949:2016 for the China site.
- Automotive focus: wire harness, battery cable and custom overmolded cable assemblies.
Trade-offs:
- Strength: a published ISO 9001 certificate for its US and Mexico sites, and IATF 16949 at its China site.
- Limit: the company’s own site lists IATF 16949 for the China site only, so ask for IATF status at whichever site would build your US-bound harness.
Sumitomo Electric Wiring Systems (SEWS)
- Headquarters (company-stated): 27360 Drake Road, Farmington Hills, Michigan 48331.
- Products (company-stated): wiring harnesses, electronics, electrified-vehicle related products, components and electric wire.
- Certifications (company-stated): not published on the company’s own site (sewsus.com) as of this check. Its site navigation (About Us, Products, Careers, News, Supplier Portal, Contact) has no quality or certifications page, and two search-engine queries restricted to the sewsus.com domain returned no results for certification terms.
Trade-offs:
- Strength: a product list that includes electrified-vehicle items, from a North American headquarters.
- Limit: the company’s own site does not list its harness plant locations in this pass, so ask for them before assuming a US build location. It also does not publish certifications, so ask for the current certificate covering whichever plant would build your harness.
How do I choose between these suppliers?
- Match certifications to your buyer. If you supply OEMs or Tier 1s, ask for the current certificate for the specific site that will build your harness, not the group certificate.
- Confirm the build location. Headquarters and production sites are often different. Ask for the plant address in writing.
- Test prototype speed. Send the same drawing to two or three suppliers and compare lead times and questions.
- Ask about high-voltage capability if your vehicle is electrified.
- Check fit with your volume. Large Tier 1 suppliers and small contract shops serve different programmes.
Ready to request a quote?
Sponsored (Cloom Tech): If you want Cloom Tech to quote your harness, send your drawing, expected volumes and target certifications. Request a quote at the Cloom Tech contact page.
