EV Wire Harness Manufacturing: Challenges and Crimping Requirements
How EV wire harnesses differ from ICE vehicles — high-voltage crimping, larger conductors, shielded cables, aluminum wiring, and quality requirements explained.
Shivam Das
Marketing Head, Anjali Machine Tools
21 July 2025
The transition from internal combustion engine (ICE) vehicles to electric vehicles (EV) is transforming wire harness manufacturing. EVs introduce entirely new high-voltage harness subsystems that demand different conductors, different terminals, different crimping techniques, and stricter quality requirements.
India’s EV market sold 2.05 million units in FY25 (22% growth) with a government target of 30% EV sales by 2030. For wire harness manufacturers — and the crimping tool suppliers who serve them — understanding these new requirements is essential to capturing this growing market.
How EV Harnesses Differ from ICE
Voltage Architecture
ICE vehicles operate on 12-14V systems. EVs use 400V platforms as the current mainstream, with next-generation vehicles from Hyundai, Porsche, and Kia adopting 800V architectures. This represents a 30x to 60x increase in operating voltage.
Conductor Sizes
ICE vehicle harnesses use wire gauges from 0.35 mm2 to 6 mm2 for most circuits, with battery cables up to 25 mm2. EV high-voltage harnesses use conductors from 10 mm2 to 95 mm2 (sometimes 120 mm2) for the main traction circuit connecting battery, inverter, and motor.
Cable Construction
| Feature | ICE Harness | EV High-Voltage Harness |
|---|---|---|
| Insulation | PVC or XLPE | Silicone rubber or XLPE rated 600-1,000V |
| Shielding | None (most circuits) | Mandatory braided copper or aluminum foil |
| Conductor | Copper only | Copper or aluminum |
| Color coding | Various | Orange (mandatory for HV per ISO standard) |
| Temperature rating | -40 to +105 degrees C | -40 to +150 degrees C (up to +180 degrees C near motor) |
Harness Complexity
While EVs eliminate some ICE-specific wiring (no exhaust sensors, fuel injection, complex transmission), they add new high-voltage subsystems: battery-to-inverter cables, on-board charger wiring, DC-DC converter connections, thermal management circuits, and battery management system (BMS) harnesses.
The net result: EVs often have similar total wire length to ICE vehicles, but with 15-25% of the harness weight now in high-voltage cabling — a category that barely existed in conventional vehicles.
New Crimping Requirements for EV Harnesses
Larger Terminals and Higher Force
HV crimping involves terminals sized for 10-120 mm2 cables, requiring significantly more force than standard automotive crimping. Standard 1-2 ton bench presses are insufficient — HV crimping needs 10-80 ton hydraulic presses with specialized dies.
For wire gauges in the 10-20 mm2 range, AMT’s Pneumatic Crimping Applicator provides the air-powered force needed without a hydraulic press. It handles closed tube terminals in sizes 10-12 without applicator changes.
Aluminum Conductors
The shift from copper to aluminum in HV cables is accelerating (aluminum is 60% lighter per unit conductivity). Aluminum crimping requires:
- Different crimp profiles than copper (compensating for aluminum’s softness and oxide formation)
- Contact grease applied before crimping to prevent oxide buildup at the crimp interface
- Modified die geometry for proper compression
- Bimetallic joint management where aluminum wire meets copper terminal
Shield Termination
Every HV cable requires electromagnetic shielding to contain EMI emissions. The shield — typically braided copper — must be terminated at each end, either crimped to a shield ring/ferrule or folded back and clamped. This is a processing step that does not exist in standard low-voltage harness manufacturing and requires specialized tooling.
Multi-Step Processing
A single HV cable termination may require five process steps — compared to two (strip and crimp) for standard low-voltage wire:
- Outer jacket stripping
- Shield cutting and folding back
- Shield ring crimping
- Inner insulation stripping
- Terminal crimping
Stricter Quality Requirements
HV crimp quality is far more critical because a poor crimp at 400V+ creates resistance, which generates heat, which can cause fires. Quality requirements include:
- Crimp force monitoring on every crimp — not optional for HV connections
- Cross-section analysis for every terminal/wire qualification
- Pull force requirements 2-5x higher than standard automotive (larger conductors)
- Electrical resistance below 0.3 milliohms for high-current connections
- USCAR-37 and LV216 compliance for high-voltage applications
Standards for EV Wire Harness
| Standard | Scope |
|---|---|
| USCAR-21 | Crimp connections for 0-48V (standard automotive) |
| USCAR-37 | Extension to 60-600V high-voltage applications |
| LV216 | German OEM standard for HV cables and connectors |
| ISO 19642 | HV harness requirements |
| ISO 6722 | General automotive cable specifications |
| IEC 62196 | Charging connector standards |
India’s EV Wire Harness Opportunity
Market Data
- India’s EV market: 2.05 million units sold in FY25, projected 10 million annually by 2030
- EV harness segment CAGR: 5.26-7.12% vs. 3.81% for overall wire harness market
- High-voltage systems growing at 5.88% CAGR
- Battery-electric vehicle harness demand growing at 7.12% CAGR
Major Indian EV Programs Driving Harness Demand
- Tata Motors: Nexon EV, Punch EV, Curvv EV — India’s largest EV manufacturer
- Mahindra: XEV 9e, BE 6 — new born-electric platforms
- Mercedes-Benz India: Manufacturing the EQS 580 luxury EV in Chakan, Pune
- Bajaj Auto: Chetak electric scooter manufactured in Pune
- Ather, Ola Electric: Electric two-wheeler manufacturers with growing production
Investment in EV Harness Capabilities
Major wire harness manufacturers are investing in India’s EV transition:
- Motherson Group — expanding HV harness capabilities for European and Indian OEMs
- Minda Corporation — developing EV-specific product lines including HV wiring and BMS harnesses
- Yazaki India — investing in HV harness lines for Tata Motors EV programs
- Aptiv — expanding India operations for EV electrical architecture
What Wire Harness Manufacturers Should Do Now
1. Assess Your Crimping Equipment
Standard automotive crimping applicators handle 0.35-6 mm2 wire. EV high-voltage crimping requires equipment for 10-120 mm2. Evaluate whether your current presses and applicators can handle the larger conductors.
AMT’s Pneumatic Crimping Applicator bridges the gap for 10-20 mm2 wire, handling EV auxiliary and mid-power circuits without the cost of a hydraulic press.
2. Invest in Quality Testing
HV connections demand higher quality assurance than standard automotive. At minimum:
- Crimp force monitoring for 100% in-process verification
- Cross-section analysis for process qualification
- Pull testing at higher force levels for larger conductors
3. Train Your Workforce
HV harness assembly requires trained technicians who understand electrical safety, ESD precautions, and HV crimp process control. This is a significant upskilling requirement.
4. Understand the Standards
Review USCAR-21 for standard automotive and USCAR-37 for HV applications. Ensure your quality system meets IPC-A-620 Class 2 at minimum.
Conclusion
The EV transition is not a future event — it is happening now. Indian wire harness manufacturers who invest in HV-capable crimping equipment, quality systems, and workforce training today will be positioned to capture the fastest-growing segment of the wire harness market.
Anjali Machine Tools supports the EV transition with crimping applicators for standard and extended wire gauge ranges, the Push & Pull Load Tester for crimp validation, and professional crimp analysis services.
Based in Pune — where Mercedes-Benz manufactures the EQS 580 and Bajaj produces the Chetak EV — we are at the center of India’s EV manufacturing ecosystem. Contact us to discuss your EV harness crimping requirements.