Premier Manufacturer
Custom car wire harnesses are essential for reliable power and signal transmission in modern vehicles.
Romtronic designs and manufactures application-specific automotive wire harnesses for passenger cars, commercial vehicles, and new-energy platforms. Our harnesses are built to meet demanding requirements for electrical stability, mechanical durability, and long-term system reliability.
From engine systems and lighting circuits to infotainment and sensor networks, we support both prototype builds and volume production with consistent quality control.
Our customized car wiring harnesses
Below are examples of custom automotive wire harnesses we manufacture. If you need additional references or similar projects, our team can share more application samples upon request.
Product Advantages
Our automotive wire harnesses are developed under automotive-grade manufacturing and quality systems.
Full customization of wire type, gauge, length, connectors, sealing, shielding, and protective structures
OEM & ODM project support, from drawing review to mass production
Electrical validation, including continuity, insulation resistance, and high-voltage testing
Designed for vibration resistance, thermal stability, and harsh automotive environments
Manufacturing aligned with RoHS and IATF 16949 quality system requirements
PPAP support available, including PFMEA/DFMEA, control plans, process flow, dimensional reports, material certifications, and sample validation
Each harness is built using automotive-grade conductors, terminals, insulation materials, and mechanical protection components to ensure safe and reliable integration into vehicle systems.
Automotive Wire Harness Manufacturing Process
Our automotive harness programs follow a controlled workflow to ensure consistency, traceability, and electrical reliability.
Design & Engineering Review
Evaluation of drawings, electrical requirements, routing conditions, and manufacturability.
Prototyping & Sample Validation
Prototype harnesses are produced to verify form, fit, and function before production approval.
Wire Processing & Sub-Assembly
Cutting, stripping, marking, pre-assembly, and installation of tubing, sealing, and protection components.
Terminal Crimping & Mechanical Assembly
Automotive-grade crimping and mechanical assembly to ensure secure electrical and mechanical performance.
Final Assembly & Electrical Testing
Harnesses are assembled to layout boards and 100% tested for continuity, short circuits, and insulation integrity.
Areas of application
Our harnesses are widely used in:
- Passenger cars and commercial vehicles
- Electric vehicles (EVs) and hybrid cars
- Heavy-duty trucks and off-road machinery
- Navigation, lighting, dashboard, and control systems
Partner with a trusted automotive wiring harness manufacturer that knows your industry and delivers on time, every time.
Types of car wiring harness
There are 11 types of automobile wiring harnesses: Engine 2nd wiring harness, Engine room wiring harness, Main wiring harness, Left front door wiring harness, Body wiring harness, Left rear door wiring harness, Taillight wiring harness, Interior light wiring harness, Right rear door wiring harness, Right front door wiring harness, and E.F.I. wiring harness. The vehicle’s LHD and RHD are different since the wiring harness circuit position is a signal. Please refer to the LHD and RHD pictures below to distinguish between them precisely.
LHD and RHD vehicles have slightly different wiring harness circuit locations, please see the pictures below.
Frequently Asked Questions (FAQs)
Q1: What’s included in a custom car wire harness?
A custom harness includes wires, connectors, terminals, tubing, sleeving, and labels—built to your layout and voltage requirements.
Q2: Do you offer sample production before mass orders?
Yes. We support prototyping for testing and fitment before scaling to mass production.
Q3: What is your typical lead time?
Prototypes: 5–7 days.
Mass production: 2–3 weeks depending on complexity and order size.
Q4: Can you match harnesses from existing samples?
Absolutely. You can send us your sample, and we’ll reverse-engineer it for exact match or improvement.
Q5: What vehicle types can you support?
We support wiring for EVs, ICE vehicles, ATVs, off-road vehicles, motorcycles, classic cars, and more.
Get in Touch for Custom Automotive Wiring Solutions
With years of experience serving the automotive industry, Romtronic delivers high-quality, reliable custom wire harnesses for a wide range of applications — from main power distribution and in-vehicle entertainment systems to sensor controls and CAN communication.
To request a quote or sample, feel free to reach out to us directly — our engineering team will get back to you within 12 hours with expert support and tailored solutions.
You can also reach us at:
📧 Email: info@romtronic.com
📞 Phone: (+86) 199-2816-5824
We look forward to being your trusted partner for automotive wire harness solutions.