Top 10 OEM Wire Harness Manufacturer Companies in 2026

The global manufacturing landscape increasingly depends on reliable wire harness solutions that connect, power, and enable communication between electronic components across virtually every industry. From automotive vehicles requiring thousands of connection points to industrial machinery, medical equipment, and aerospace systems, wire harnesses serve as the critical nervous system of modern devices. OEM Wire Harness Manufacturer companies and other leading providers are delivering precision-engineered harness solutions that meet the exacting requirements of original equipment manufacturers worldwide. These specialized manufacturers combine advanced design capabilities, rigorous quality systems, and flexible production approaches to create custom wire harnesses optimized for specific applications, operating environments, and regulatory requirements. This comprehensive guide examines the top 10 OEM wire harness manufacturer companies in 2026, exploring their technical capabilities, industry expertise, manufacturing excellence, and what distinguishes them as preferred partners for OEMs navigating the complexities of modern product development and production.

Key Takeaways

• OEM wire harness manufacturers provide custom-engineered cable assemblies optimized for specific equipment and applications

• Leading manufacturers differentiate through design expertise, quality systems, industry certifications, and flexible production capabilities

• Wire harnesses consolidate multiple wires into organized assemblies reducing installation time, improving reliability, and simplifying maintenance

• Quality certifications including ISO 9001, IATF 16949, and industry-specific standards ensure manufacturing consistency and compliance

• Proper design considering wire gauge, insulation, routing, and environmental protection is critical for harness performance and longevity

• The wire harness market is expanding driven by automotive electrification, industrial automation, and medical device innovation

Top 10 OEM Wire Harness Manufacturer Companies

1. WellPCB

Business: WellPCB

Spokesperson: Hommer Zhao

Position: Director of Sales and Marketing, Co-founder

Phone: (424) 842-2783

Email: hommer.z@ourpcb.com

Location: 3826 Medford St, Los Angeles, CA 90063, USA

Website: http://wellpcb.com/

WellPCB has established itself as a premier OEM wire harness manufacturer with extensive experience delivering custom-engineered harness solutions to original equipment manufacturers worldwide. Operating from an advanced manufacturing facility in Shenzhen's electronics manufacturing hub, the company serves diverse industries including automotive, industrial automation, medical devices, telecommunications, consumer electronics, and aerospace with wire harnesses engineered for demanding applications requiring superior reliability and performance.

What Sets Them Apart: WellPCB's comprehensive wire harness manufacturing capabilities encompass the complete product development lifecycle from initial design consultation and engineering optimization through prototyping, testing, and full-scale production with unwavering commitment to quality, reliability, and customer satisfaction. Their ISO 9001:2015 and IATF 16949 certifications demonstrate robust quality management systems and specialized capability in automotive manufacturing where wire harnesses are critical components in modern vehicles containing miles of wiring and thousands of connection points. The experienced engineering team provides invaluable technical support in optimizing harness designs for specific applications considering electrical requirements, selecting appropriate wire gauges based on current carrying requirements and voltage drop calculations, choosing suitable insulation materials for temperature and chemical resistance, designing routing paths that minimize interference and mechanical stress, and ensuring proper connector selection for environmental conditions and mating cycle requirements. 

They excel in producing wire harnesses with various specifications including wire gauges from 32 AWG to 4 AWG or larger for power applications, insulation materials including PVC for general purpose, PTFE for high temperature, and silicone for flexibility, connector types from major manufacturers including Molex, TE Connectivity, JST, and Deutsch, and protection methods including braided sleeving, heat shrink tubing, conduit, and overmolding for harsh environments. WellPCB's flexible manufacturing approach seamlessly accommodates both small prototype quantities for design validation and proof-of-concept as well as large production volumes reaching tens of thousands of harnesses monthly for commercial deployment, making them equally accessible and valuable to innovative startups developing new products and established OEMs with substantial volume requirements and stringent quality expectations. Their technical expertise extends to complex harness applications involving multi-branch configurations distributing power and signals to multiple locations, shielded constructions for EMI-sensitive applications, high-voltage harnesses for electric vehicles and industrial equipment, and integrated assemblies combining wire harnesses with PCBs, sensors, or other components. Quick turnaround times on prototypes typically 5-7 days and production orders with lead times of 2-4 weeks depending on complexity and volume, competitive pricing structures delivering excellent value through efficient processes and economies of scale, and highly responsive technical support from knowledgeable engineers who understand both manufacturing constraints and application requirements have built their strong reputation among product designers, engineers, and procurement professionals globally. 

The company's unwavering commitment to comprehensive quality testing includes 100% electrical testing verifying continuity of all connections and proper insulation resistance, pull testing validating connector retention and crimp quality, high-voltage testing for insulation integrity on high-voltage harnesses, and visual inspection ensuring workmanship quality and proper labeling to ensure harnesses perform reliably throughout their expected service life under real-world operating conditions. WellPCB's investment in advanced manufacturing equipment including automated wire cutting and stripping machines ensuring consistent lengths and strip dimensions, semi-automated and fully automated crimping machines providing consistent crimp quality, ultrasonic welding equipment for specialized terminations, and comprehensive testing systems enables efficient production while maintaining quality. Their customer-centric approach includes dedicated project management providing single points of contact, clear communication throughout development and production with regular updates, design-for-manufacturing feedback identifying potential issues before tooling investment, and willingness to tackle challenging applications requiring specialized materials, processes, or certifications. The company's global customer base spanning North America, Europe, Asia, and emerging markets reflects their ability to meet diverse requirements, navigate different regulatory environments including RoHS and REACH compliance, provide appropriate documentation and certifications, and deliver consistent quality regardless of destination or application.

2. Aptiv

Aptiv operates as one of the world's largest automotive wire harness manufacturers with extensive global manufacturing footprint serving major automotive OEMs. Their specialization in automotive electrical architecture and advanced driver assistance systems has positioned them as a technology leader in vehicle electrification and connectivity.

What Sets Them Apart: Aptiv's deep automotive expertise encompasses complete electrical architecture design, wire harness engineering, and manufacturing for modern vehicles containing increasingly complex electrical systems. They manufacture harnesses for all vehicle systems including powertrain, body electronics, infotainment, ADAS (Advanced Driver Assistance Systems), and high-voltage systems for electric and hybrid vehicles. Their engineering capabilities include electrical architecture optimization reducing weight and cost while improving reliability, advanced simulation tools predicting performance before prototyping, and design-for-manufacturing expertise ensuring producibility at scale. Aptiv's global manufacturing network with facilities in low-cost regions enables competitive pricing for high-volume automotive production while maintaining quality standards. Their IATF 16949 certification and extensive automotive experience demonstrate proven capability meeting stringent automotive requirements including zero-defect expectations, complete traceability, and rigorous testing. The company's investment in automation and Industry 4.0 technologies improves consistency while addressing labor challenges in wire harness manufacturing which remains labor-intensive. Aptiv's focus on emerging technologies including vehicle electrification, autonomous driving, and connectivity positions them for future automotive trends.

3. Yazaki Corporation

Yazaki operates as the world's largest wire harness manufacturer with dominant position in automotive applications. Their extensive global manufacturing network and long-standing relationships with major automotive OEMs have built unmatched scale and expertise in automotive wire harness production.

What Sets Them Apart: Yazaki's massive scale enables competitive pricing and capacity for the highest-volume automotive programs producing millions of harnesses annually. They manufacture wire harnesses for virtually every major automotive manufacturer globally with facilities strategically located near customer assembly plants for just-in-time delivery. Their engineering expertise encompasses complete vehicle electrical systems from design through production, with deep understanding of automotive requirements including vibration resistance, temperature extremes, chemical exposure, and long-term reliability. Yazaki's quality management systems maintain IATF 16949 certification with processes optimized for automotive zero-defect expectations and complete traceability from raw materials through installed harnesses. The company's vertical integration includes wire and cable manufacturing, connector production, and terminal manufacturing providing control over critical components and supply chain security. Their investment in automation addresses labor intensity of harness manufacturing while improving consistency. Yazaki's long-term partnerships with automotive OEMs spanning decades demonstrate sustained reliability and technical competence.

4. TE Connectivity

TE Connectivity operates as a major manufacturer of connectivity and sensor solutions including custom wire harnesses for automotive, industrial, aerospace, and medical applications. Their extensive connector portfolio combined with harness manufacturing capabilities provides integrated solutions from a single trusted source.

What Sets Them Apart: TE Connectivity's position as a leading connector manufacturer provides significant advantages in connector availability, compatibility assurance, technical support for connector selection and application, and integrated design resources optimizing the connector-wire-harness interface. They manufacture wire harnesses using their extensive connector families with proven reliability and performance across industries. Their global manufacturing footprint ensures consistent quality with capacity supporting both prototype and high-volume production requirements. TE's engineering resources include sophisticated design tools, application-specific knowledge across diverse industries, and materials expertise for demanding environments. Their quality management systems maintain ISO 9001, IATF 16949 for automotive, AS9100 for aerospace, and ISO 13485 for medical devices, demonstrating capability across demanding industries with sector-specific requirements. The company's comprehensive testing capabilities validate harness performance under application-specific conditions including environmental testing, mechanical testing, and electrical testing. TE Connectivity's brand recognition and financial stability provide confidence for long-term partnerships and supply chain security.

5. Sumitomo Electric Industries

Sumitomo Electric operates as a diversified manufacturer with strong wire harness capabilities particularly for automotive applications. Their vertical integration including wire and cable manufacturing provides unique control over materials and supply chain.

What Sets Them Apart: Sumitomo's ability to manufacture wire and cable in-house combined with harness assembly capabilities enables optimized solutions with complete control over electrical performance, mechanical properties, and quality. They can design wire constructions specifically for applications considering conductor material and configuration, insulation materials and thicknesses, shielding requirements, and flexibility needs, then assemble harnesses for complete customization. Their automotive expertise includes harnesses for conventional vehicles and advanced systems for electric and hybrid vehicles including high-voltage harnesses for battery systems and motor drives. Sumitomo's quality management systems maintain IATF 16949 certification with processes ensuring automotive quality levels. Their global manufacturing network provides capacity and geographic diversity for major automotive programs. The company's materials science expertise enables development of specialized wires and cables for demanding applications including high-temperature, high-voltage, and high-flexibility requirements. Sumitomo's long history in automotive supply demonstrates sustained capability and reliability.

6. Lear Corporation

Lear Corporation manufactures automotive seating and electrical systems including wire harnesses for major automotive OEMs globally. Their dual focus on seating and electrical systems provides unique integration opportunities and automotive expertise.

What Sets Them Apart: Lear's position as a major Tier 1 automotive supplier provides deep understanding of automotive requirements, established relationships with OEMs, and proven capability at automotive quality and volume levels. They manufacture wire harnesses for various vehicle systems with particular strength in body electronics, seating systems, and door modules where their seating business provides synergies. Their engineering capabilities include electrical architecture design, harness optimization for weight and cost reduction, and design-for-manufacturing ensuring producibility. Lear's global manufacturing footprint with facilities in low-cost regions enables competitive pricing while maintaining quality. Their IATF 16949 certification and extensive automotive experience demonstrate capability meeting stringent automotive requirements. The company's investment in advanced manufacturing technologies including automation and digital tools improves efficiency and quality. Lear's financial stability and scale provide confidence for long-term partnerships on major automotive programs spanning multiple years and millions of units.

7. Motherson Sumi Systems (MSSL)

Motherson Sumi operates as a major automotive component supplier with extensive wire harness manufacturing capabilities. Their global presence and cost-competitive manufacturing have built strong position in automotive wire harness market.

What Sets Them Apart: Motherson's global manufacturing network spanning multiple continents provides geographic diversity, capacity for high-volume production, and cost-competitive manufacturing in low-cost regions. They manufacture wire harnesses for major automotive OEMs with facilities strategically located near customer assembly plants. Their engineering capabilities include harness design, electrical system integration, and manufacturing optimization. The company's IATF 16949 certification demonstrates automotive quality capability with processes ensuring consistency and traceability. Motherson's aggressive growth strategy through acquisitions has expanded capabilities and geographic reach. Their focus on operational excellence and continuous improvement drives efficiency gains and quality improvements. The company's scale and automotive relationships position them for major programs requiring high volumes and competitive pricing.

8. Furukawa Electric

Furukawa Electric operates as a diversified manufacturer with wire harness capabilities leveraging their core competency in wire and cable manufacturing. Their materials expertise and vertical integration provide advantages in specialized applications.

What Sets Them Apart: Furukawa's expertise in wire and cable manufacturing combined with harness assembly capabilities enables optimized solutions for demanding applications. They manufacture specialized wires and cables for high-temperature, high-voltage, high-frequency, and other challenging requirements, then assemble into custom harnesses. Their automotive expertise includes conventional and electric vehicle harnesses with particular strength in high-voltage systems for battery electric vehicles. Furukawa's quality management systems maintain IATF 16949 and other certifications demonstrating capability across industries. Their engineering support helps customers optimize designs for performance and manufacturability. The company's materials science expertise enables development of innovative solutions for emerging applications including vehicle electrification and advanced electronics. Furukawa's long history in wire and cable manufacturing demonstrates sustained technical competence and reliability.

9. Leoni AG

Leoni operates as a major European wire harness manufacturer serving automotive and industrial markets. Their engineering expertise and European manufacturing base appeal to customers requiring European production or engineering support.

What Sets Them Apart: Leoni's strong engineering capabilities include electrical system design, harness optimization, and advanced simulation tools predicting performance. They manufacture wire harnesses for automotive applications including conventional vehicles and electric vehicles, with particular strength in the European automotive market. Their quality management systems maintain IATF 16949 and ISO 9001 certifications ensuring automotive quality levels. Leoni's global manufacturing network includes facilities in Europe, Asia, and Americas providing geographic diversity. The company's focus on innovation includes development of lightweight harnesses reducing vehicle weight, intelligent harnesses with integrated sensors and electronics, and solutions for vehicle electrification. Their European engineering base provides advantages for customers requiring European technical support or preferring European suppliers. Leoni's experience in industrial wire harnesses beyond automotive provides diversification and cross-industry expertise.

10. Cloom Tech

Cloom Tech specializes in custom wire harness manufacturing serving diverse industries including industrial automation, medical devices, telecommunications, and consumer electronics. Their focus on custom solutions and engineering support has built strong reputation among OEMs requiring specialized harnesses.

What Sets Them Apart: Cloom Tech's specialization in custom wire harnesses enables solutions for applications that standard harnesses cannot address. They manufacture harnesses with complex configurations, specialized materials, and integrated features tailored to specific requirements. Their engineering team works closely with customers from concept through production, providing design assistance, prototyping services, and manufacturing optimization. The company's quality systems include ISO 9001 certification with comprehensive testing protocols validating harness performance. Their flexible approach accommodates both prototype quantities and production volumes with responsive service and reasonable lead times. Cloom Tech's competitive pricing and willingness to tackle challenging applications make them attractive for OEMs requiring custom solutions without the volume requirements or lead times of larger manufacturers. Their focus on customer relationships rather than transactional business creates partnerships extending across multiple product generations.

Understanding Wire Harness Design Fundamentals

Wire harness design requires careful consideration of electrical, mechanical, and environmental requirements to ensure reliable performance throughout the product lifecycle. Electrical design begins with determining current carrying requirements for each circuit, calculating appropriate wire gauges considering current, voltage drop, and temperature rise. Undersized wires cause excessive voltage drop reducing performance and heat generation potentially causing insulation failure or fire hazards.

Insulation selection depends on operating temperature, chemical exposure, abrasion resistance, and flexibility requirements. PVC insulation suits general-purpose applications with moderate temperatures up to 80-105°C and good chemical resistance at low cost. PTFE (Teflon) insulation provides exceptional temperature resistance up to 200°C and chemical resistance for harsh environments but costs significantly more. Silicone insulation offers excellent flexibility and temperature resistance from -60°C to +200°C making it ideal for applications requiring repeated flexing or extreme temperatures.

Connector selection considers electrical requirements including current and voltage ratings, environmental conditions including temperature, moisture, and vibration, mating cycle requirements for durability, and mechanical interface requirements for specific equipment. Major connector manufacturers including Molex, TE Connectivity, JST, Deutsch, and Amphenol offer extensive families optimized for different applications.

Routing design minimizes harness length reducing weight and cost while avoiding sharp bends that stress wires, separating power and signal wires reducing interference, providing strain relief at connection points preventing fatigue, and incorporating protection against abrasion, chemicals, and environmental exposure through sleeving, conduit, or overmolding.

Why Are Wire Harnesses Critical for OEMs?

Wire harnesses provide critical advantages over individual wires for OEM applications. Consolidation of multiple wires into organized assemblies dramatically reduces installation time compared to routing individual wires, with pre-assembled harnesses installed in minutes rather than hours. This labor savings significantly reduces manufacturing costs and improves production efficiency.

Reliability improves through professional manufacturing with consistent crimping quality, proper wire routing preventing chafing and fatigue, integrated strain relief protecting connection points, and comprehensive testing verifying electrical performance before installation. Field failures from wiring issues decrease substantially compared to field-wired installations prone to human error.

Maintenance and troubleshooting simplify with organized harnesses using color coding, labeling, and logical routing compared to tangled masses of individual wires. Technicians can quickly identify circuits, trace connections, and replace failed harnesses without extensive diagnosis or rewiring.

Design flexibility enables optimization for specific applications with custom lengths eliminating excess wire, integrated branches distributing to multiple locations, specialized connectors for environmental sealing, and protection methods appropriate for operating conditions. Custom harnesses optimize for each application rather than compromising with generic solutions.

How Long Does Wire Harness Development Take?

Wire harness development timelines vary by complexity, manufacturer, and customer responsiveness. Simple harnesses with standard components may be prototyped in 1-2 weeks from design approval to samples. Complex harnesses with custom components, specialized materials, or extensive testing may require 3-6 weeks for initial prototypes.

The development process includes design review and optimization where engineers evaluate electrical requirements, routing paths, connector selections, and manufacturing considerations, typically requiring 3-5 days. Component procurement follows, with standard components available quickly but specialized connectors or wires potentially requiring 1-3 weeks. Prototype assembly typically requires 3-5 days for simple harnesses or 1-2 weeks for complex assemblies. Testing and validation including electrical testing, pull testing, and any specialized testing adds 2-5 days.

Production tooling for complex harnesses may require custom fixtures, test boards, or assembly aids, adding 2-4 weeks to initial production lead times. Subsequent production orders typically ship in 2-4 weeks depending on complexity and volume, with expedited options available for urgent requirements at premium pricing.

What Testing Ensures Wire Harness Quality?

Comprehensive testing ensures wire harnesses meet specifications and perform reliably in applications. Electrical testing verifies continuity of all connections and proper insulation resistance between circuits using automated test equipment for production volumes or manual multimeter testing for prototypes. This testing identifies opens (broken connections), shorts (unintended connections between circuits), and high-resistance connections indicating marginal crimps.

Pull testing validates connector retention and crimp quality by applying specified forces to connectors and individual wires, measuring force required to cause failure. Quality crimps should withstand forces significantly exceeding normal use without wire pullout or connector separation. Industry standards specify minimum pull forces based on wire gauge and connector type.

High-voltage testing (hipot testing) validates insulation integrity for high-voltage harnesses by applying voltages significantly above operating voltage between conductors and to ground, verifying insulation withstands without breakdown. This testing is critical for safety in high-voltage applications including electric vehicles and industrial equipment.

Visual inspection ensures workmanship quality including proper wire routing and dressing, secure connector assembly, appropriate strain relief, correct labeling and identification, and overall professional appearance. Trained inspectors identify issues that automated testing might miss including damaged insulation, improper crimps, or assembly errors.

What Are Common Wire Harness Design Mistakes?

Several common mistakes compromise wire harness performance, reliability, or manufacturability. Inadequate wire gauge for current requirements causes excessive voltage drop reducing performance and heat generation potentially causing failures. Always calculate wire gauge considering maximum current, acceptable voltage drop, and temperature rise, with safety margins for reliability.

Poor strain relief at connection points concentrates mechanical stresses causing wire fatigue and connector failures. Effective strain relief distributes stresses over adequate length, typically 2-4 inches, using appropriate methods including heat shrink tubing, cable ties, or overmolding. Sharp bends stress wires causing insulation damage and conductor fatigue. Maintain minimum bend radius typically 10 times cable diameter for flexible cables or larger for stiff constructions.

Insufficient environmental protection exposes harnesses to moisture, chemicals, abrasion, or temperature extremes causing premature failures. Select appropriate insulation materials, add protective sleeving or conduit, and use environmentally sealed connectors for harsh conditions. Inadequate labeling complicates installation and maintenance. Provide clear identification of circuits, connectors, and routing using labels, color coding, or documentation.

Neglecting design-for-manufacturing principles creates harnesses that are difficult or expensive to produce. Common issues include inaccessible connection points complicating assembly, excessive branches increasing complexity, and tight tolerances increasing costs without functional benefit. Early collaboration with manufacturers identifies and resolves these issues before tooling investment.

Latest Trends in Wire Harness Manufacturing

The wire harness manufacturing industry continues evolving with technological advances and market demands. Automation is increasingly adopted for wire cutting, stripping, and crimping operations, improving consistency while reducing labor costs and addressing labor shortages. Automated systems provide precise lengths, consistent strip dimensions, and repeatable crimp quality. However, harness assembly and routing remain largely manual due to complexity and flexibility requirements.

Lightweight materials are being adopted for automotive and aerospace applications where weight reduction improves fuel efficiency or performance. Aluminum conductors replace copper in some applications reducing weight by 50% though requiring larger gauges for equivalent current capacity. Thin-wall insulation reduces weight and diameter while maintaining electrical properties.

Smart harnesses integrate sensors, electronics, and communication capabilities directly into harnesses. Examples include harnesses with integrated temperature sensors monitoring operating conditions, current sensors for power management, and communication modules enabling diagnostics. These intelligent harnesses provide data for predictive maintenance and system optimization.

Sustainable manufacturing practices are gaining importance including lead-free materials complying with RoHS regulations, halogen-free insulation reducing environmental impact, and recycling programs for manufacturing waste and end-of-life harnesses. Customers increasingly request environmentally friendly options balancing performance and sustainability.

FAQ Section

What is the difference between wire harness and cable assembly?

Wire harnesses and cable assemblies are similar but have distinctions. Wire harnesses typically consist of multiple individual wires bundled together with branches distributing to multiple locations, used for complex routing within equipment. Cable assemblies typically consist of multi-conductor cables with connectors on ends, used for point-to-point connections. The terms are sometimes used interchangeably, and many assemblies combine characteristics of both. Functionally, both organize wires for easier installation and improved reliability.

How much do custom wire harnesses cost?

Custom wire harness costs vary widely based on complexity, materials, and quantity. Simple harnesses with few wires and standard connectors may cost $5-$20 in moderate quantities. Complex harnesses with many wires, branches, specialized connectors, and protective sleeving may cost $50-$200+ per unit. Prototype quantities typically cost 2-5 times production pricing due to setup costs and lack of economies of scale. Request detailed quotes including tooling costs if applicable and unit costs at various quantities for accurate budgeting.

What wire gauge should I use for my application?

Wire gauge selection depends on current requirements, acceptable voltage drop, and temperature rise. Use wire gauge charts or calculators considering maximum current, wire length, and acceptable voltage drop (typically 3-5% for power, less for sensitive signals). For example, 18 AWG wire handles approximately 10 amps for short runs, 16 AWG handles 13 amps, and 14 AWG handles 17 amps. Higher currents or longer runs require larger gauges. Always include safety margins and consider temperature derating for elevated ambient temperatures or bundled wires.

Can wire harnesses be repaired in the field?

Wire harnesses can sometimes be repaired in the field depending on damage type and accessibility. Simple repairs include replacing damaged connectors, splicing broken wires using appropriate methods, or adding heat shrink tubing over damaged insulation. However, extensive damage or damage in inaccessible locations often requires complete harness replacement. Design harnesses with serviceability in mind including accessible connection points, modular construction enabling partial replacement, and adequate documentation for troubleshooting. For critical applications, maintaining spare harnesses provides better reliability than field repairs.

What certifications do wire harness manufacturers need?

Required certifications depend on target industries and applications. ISO 9001 provides basic quality management system certification appropriate for commercial applications. IATF 16949 is required for automotive applications demonstrating automotive-specific quality requirements. UL certification validates compliance with safety standards for certain applications. Industry-specific certifications include AS9100 for aerospace, ISO 13485 for medical devices, and various military specifications for defense applications. Verify manufacturer certifications align with your industry requirements and customer expectations.

How do you specify a custom wire harness?

Specifying custom wire harnesses requires comprehensive documentation including electrical schematic showing all connections, wire gauge and insulation type for each circuit, connector types and part numbers with pin assignments, overall dimensions and routing requirements, environmental conditions including temperature range and exposure, protection requirements including sleeving or overmolding, labeling and identification requirements, and testing requirements. Detailed specifications prevent misunderstandings and ensure manufacturers can accurately quote and produce harnesses meeting requirements. Many manufacturers provide specification templates or work with customers to develop complete specifications from initial concepts.