Cable Assemblies for Automotive & EV

An automotive harness is asked to survive vibration it cannot damp, temperature swings it cannot avoid, and fluids it cannot repel — for years, without access. The assembly is the easy part; proving it will last is the work.

HKWIRE is a custom cable assembly manufacturer and OEM/ODM supplier in Longgang, Shenzhen. Automotive and EV harnesses are built to your drawing, with the documentation scope agreed at quotation rather than negotiated at delivery.

What this application demands

These are the constraints that change the design. Everything else is a normal cable.

Vibration: Continuous low-amplitude vibration loosens terminations and work-hardens stranded conductors at the crimp. Strain relief and retention features carry the load, not the solder joint.
Temperature cycling: Under-hood and exterior locations swing far further than cabin electronics. Jacket and overmold materials are selected for the range, not the average.
Fluid exposure: Oil, fuel, coolant and road salt. Material selection is driven by what the harness is routed past.
Connector retention and locking: Positive latching plus an overmold that supports the connector body, so vibration loads do not reach the crimp.
Abrasion and routing: Loom, sleeving and clip points. Most harness failures are chafe at a routing point, not electrical.

Typical builds

Dashcam and rear-view camera harnesses
OBD2 and J1939 adapter and extension cables
Battery-management and sense-lead assemblies
Sensor and actuator harnesses with overmolded grommets
Overmolded seals and panel feedthroughs

Automotive and EV assemblies we build

Documentation: what we provide

First-article inspection: Yes — dimensional and electrical FAI reports, produced to your format.
PPAP: We do not claim PPAP submission. If your program requires it, we will tell you at quotation so you can qualify us honestly.
Crimp verification: Pull-force testing per conductor size against IPC/WHMA-A-620 workmanship criteria, with results retained per batch.
Electrical testing: Continuity and pinout 100%. Insulation resistance, hipot and contact resistance per the agreed test scope.

IPC/WHMA-A-620 Class 3 is the workmanship criteria we build and inspect to. We state it as the standard we work against; we do not claim a certificate we do not hold.

Standards and temperature classes we design and test to

Automotive cable is specified by temperature class, not by a single “automotive rated” label. We build to the class set by the routing location in your drawing and record the evidence. Below are the long-term service temperatures from ISO 6722-1 (road-vehicle single-core cable); higher classes exist up to 250 C for the hottest engine-bay locations.

ISO 6722-1 class	Long-term service (3000 h)	Short-term (240 h)	Thermal overload (6 h)
T85 (A)	−40 to +85 C	+110 C	+135 C
T100 (B)	−40 to +100 C	+125 C	+150 C
T125 (C)	−40 to +125 C	+150 C	+175 C
T150 (D)	−40 to +150 C	+175 C	+200 C
T175 (E)	−40 to +175 C	+200 C	+225 C

The short-term and thermal-overload columns are derived from the service temperature: +25 C for 240 h and +50 C for 6 h, exactly as the standard defines. We state these as the specifications we design and inspect against; we do not claim an ISO 6722 certificate we do not hold.

USCAR-2: Connector-system performance (mechanical, electrical, environmental) for SAE-aligned programs — the envelope we design mating connectors and seals to where the program requires it.
LV 214 / LV 215: Terminal and connector performance specifications (retention, insertion/extraction, current cycling) used across the VW group and beyond; we design terminals to these envelopes where specified.
IEC 60529 (IP): Connector sealing classes — IP67 and IP69K where the harness is washed down or submerged. See our certifications and material declarations page for the current scope.

For the full temperature-class, gauge, and protection selection logic, see our automotive wire harness selection guide.

What we ask before quoting

Answer these with the drawing and the quotation will be meaningful on the first pass.

Mounting location and temperature range
Vibration profile, if you have one
Fluids the harness is routed past
Mating connector part numbers
Documentation required: FAI, dimensional, test data
Annual volume and expected order pattern

An automotive wire harness manufacturer built around documentation

IPC/WHMA-A-620 Class 3 is the workmanship criteria we build and inspect to. Crimp verification, first article inspection and electrical test results are provided to your format where you supply one. Where a full PPAP submission is required, we confirm at quotation exactly what we can support instead of discovering it at delivery.

Overmolded grommets, seals and panel feedthroughs run on tooling cut in our own tool room, and every unit passes 100% continuity and pinout testing before it is packed. High-temperature builds use our silicone harnesses. Factory audits, in person or by live video, can be arranged in advance.

Where these harnesses are used

The same build-to-print discipline applies across the vehicle; the constraints change with the location.

Body and comfort electronics: Lighting, seating, infotainment and convenience modules — low-voltage looms where routing, clip points and abrasion resistance decide service life more than temperature.
ADAS and LiDAR sensor looms: Low-loss, shielded runs to cameras, radar and LiDAR where signal integrity and EMI control matter more than current. We treat the shield and termination as part of the design, not an add-on.
In-vehicle networking: CAN, FlexRay and Automotive Ethernet (100/1000BASE-T1) links between ECUs, sensors and gateways. Twisted-pair construction and impedance control are built to the network spec on your drawing.
High-voltage and charging: Covered in the new energy, charging and energy storage section below — HV distribution, charging interfaces and BMS wiring.

What to send with your RFQ

Mounting location and temperature range
Vibration profile, if you have one, and the fluids routed past the harness
Mating connector part numbers
Documentation required — FAI, dimensional, test data — plus annual volume

Browse automotive wire harnesses for reference builds.

Send the specification and the mating connectors

We will confirm what the cable has to survive, flag anything that will cost you money without adding function, and quote against your drawing.

REQUEST A QUOTE

New energy vehicles (NEV), charging, and energy storage

Electrified platforms add a second cable problem on top of the 12 V one: high-voltage distribution, charging interfaces, and battery-management wiring, each with its own mechanical and thermal demands. The EV charging cable assembly and adapter side is built to the same print-and-document discipline as the low-voltage loom. We build these to the same print-and-document discipline as the low-voltage loom.

EV high-voltage harness — high-voltage distribution and interconnect built to the vehicle drawing.
Type 2 to NACS charging adapter cable — EV charging interface conversion for AC and DC charging paths.
V2L discharge adapter cable — vehicle-to-load power take-off for camping, tools, and backup.
Energy storage cabinet wiring harness — BMS and cabinet wiring for stationary storage tied to EV charging sites.
E-bike battery harness — light EV battery interconnect built to the pack drawing.

For the low-voltage side of the same platform, see our automotive wire harness selection guide (ISO 6722 temperature classes, gauge, and protection).

Automotive & EV cable FAQ

What is your MOQ and lead time?

Production orders start at 500 pcs and ship 14 working days after approval. Prototypes start from 1 to 50 pcs and leave in 3 working days; new overmold tooling adds about 10 working days.

Can you overmold grommets and seals?

Yes, including multi-shot seals and panel feedthroughs. Tooling is designed and cut in our own tool room; see overmolding.

Do you support PPAP?

We do not claim full PPAP submission. We supply first article inspection, crimp verification and test data to your format, and confirm any wider requirement at quotation.

Can you build to our drawing without substitutions?

Yes. Build-to-print is the default. Any proposed substitution is raised as a question with the reason, and only applied with your approval.

Can we audit the factory?

Yes. On-site audits or a live video walk-through of the molding area, assembly lines and inspection benches can be arranged in advance.

Do you supply automotive harnesses under our brand?

Yes. We build to your drawing as an OEM and ODM manufacturer and supplier, shipping from our Shenzhen factory with your part labeling and packaging.

Are you custom automotive wire harness manufacturers?

Yes. We build custom automotive wire harnesses to your drawing — OBD2 and J1939 adapters, BMS sense leads, sensor and actuator harnesses — with crimp verification and first article documentation.