Carrier for vehicle electrical signal and power transmission, connecting controllers, sensors and actuators. Divided into low‑voltage harness and high‑voltage harness.
Automotive wire harnesses and cables constitute the “nervous system” of modern vehicles. They realize signal transmission and power delivery across distributed electronic components. With vehicle electrification, high‑voltage harnesses for new‑energy vehicles bring stricter requirements for insulation, shielding and mechanical durability, while traditional low‑voltage harnesses still dominate body‑control and sensor‑signal circuits. Harness quality directly determines the reliability of the whole‑vehicle electrical architecture。
Top 10 Global Brands
Yazaki Corporation, Sumitomo Wiring Systems, Leoni, Aptiv, TE Connectivity, Prysmian Group, Furukawa Electric, Motherson Group, Visteon, Bosch. These global tier‑one suppliers provide complete low‑voltage and high‑voltage harness solutions for mainstream global OEM platforms, covering passenger cars, commercial vehicles and new‑energy‑vehicle projects.
Top 10 Chinese Domestic Brands
Huguang Co., Ltd., Changchun Jieyi, Tianhai Electronics, Derun Electronics, Ruida Reach, Weizhijie, Yingkou Abe Wiring, AVIC Jonhon Optronic Technology, Wasion Nuclear Material, Keda Li. Domestic manufacturers achieve large‑volume OEM matching, making steady progress in high‑voltage harness import‑substitution for Chinese new‑energy‑vehicle platforms.
Structural Composition
Automotive harness assemblies consist of conducting wires & cables, crimped terminals, connector housings, corrugated tubes, wrapping tapes, mounting clips, rubber grommets, fuses and relay brackets. Products are classified into low‑voltage harnesses and high‑voltage harnesses. Low‑voltage cables adopt multi‑strand copper conductors with PVC or XLPE insulation layers. High‑voltage harnesses add double‑layer insulation and metallic shielding braids, together with dedicated high‑voltage connectors for EV high‑power loops. Branched harness networks electrically interconnect all vehicle controllers, sensors and actuators.
Application
Carrier for vehicle electrical signal and power transmission, connecting controllers, sensors and actuators. Divided into low‑voltage harness and high‑voltage harness. Low‑voltage harnesses handle 12‑V signal transmission and low‑power supply. High‑voltage harnesses transfer large‑current energy among battery packs, traction motors and on‑board chargers in new‑energy vehicles.
Manufacturing Challenges
Critical challenges include strict crimp‑cross‑section quality control for wire‑terminal joints. 3‑D layout simulation prevents mechanical interference and cable abrasion. Shield‑layer termination for high‑voltage harnesses suppresses EMC interference. Batch‑to‑batch assembly consistency for multi‑branch harnesses must be guaranteed. Corrugated‑tube and taping processes are tightly controlled. Materials sustain wide temperature range from ‑40 ℃ to 125 ℃, oil contamination and salt‑fog corrosion. Anti‑release terminal design avoids loose connections under vehicle vibration. High‑voltage insulation‑withstand safety validation is mandatory. Light‑weight aluminum‑conductor harnesses bring extra process difficulties. Complex multi‑part BOM management prevents material picking mistakes in mass production.
Required Quality Documents
IATF16949 certification, APQP documents, DFMEA / PFMEA risk‑analysis report, production control plan, full‑set PPAP submission, terminal crimp cross‑section report, vibration‑shock endurance report, high‑low‑temperature cycle test report, salt‑spray corrosion report, insulation‑withstand test report, EMC validation report, IMDS material‑data sheet, RoHS and REACH compliance certificates. High‑voltage harnesses additionally require dedicated high‑voltage insulation‑test documentation.
Impact on Vehicle Performance
Harnesses serve as fundamental carrier for vehicle electrical signals and power delivery. Poor terminal crimping causes intermittent open‑circuit faults, leading to sensor‑signal dropout and ECU diagnostic trouble codes. Abraded cable insulation may trigger short‑circuit faults, blowing fuses and even bringing fire hazards. Insulation failure of high‑voltage harnesses creates severe electrical‑safety risks. Improper shielding induces electromagnetic interference and causes abnormal operation of ADAS and other controllers. Unreasonable harness routing accelerates abrasion and ageing, directly determining whole‑vehicle electrical‑system reliability and driving safety.