Application Scenarios in Body and Control System Harnesses:

1.Body Wiring Harness — Doors, Roof, and Dashboard

The body harness is the most branched sub-assembly in the entire vehicle. Each branch ends in a splice that combines power-feed wires with signal returns to door latches, window motors, and ambient lighting.

• Typical Wire Sizes: 0.35 mm² to 2.5 mm² (TPE or PVC insulation).

• Ultrasonic Advantage: Absolute consistency. Operators set the program once, and every splice produces the exact same height, width, and tensile strength.

2.Engine Compartment and Control System Harnesses

Control system harnesses connect the ECU, BCM, gateway module, and critical engine sensors (oxygen sensor, MAP, MAF, crankshaft position).

• Environmental Challenges: Must survive vibration, fluid exposure, and heat cycling from −40 °C to +125 °C.

• Ultrasonic Advantage: Delivers a gas-tight joint that resists corrosion far better than crimped butt splices.

3.Lighting and Sensor Sub-Harnesses

LED headlight modules, ADAS camera harnesses, and parking sensor loops rely on small-gauge multi-wire joints.

• Ultrasonic Advantage: Provides a compact, low-profile weld preferred over the bulkier profile of a crimped splice plus heat-shrink tubing, making it ideal for tight cavities.

4.Battery Negative and Ground Distribution Points

Even in a 12 V system, ground distribution splices may bundle 6 to 8 wires together.

• Ultrasonic Advantage: Consolidates the entire bundle into one solid copper nugget in under a second, eliminating the risk of loose strands common in crimping or resistance soldering.

Our equipment offers the following advantages:

• Comprehensive Splicing Capability: A single unit seamlessly handles wire cross-sections ranging from 0.35 mm² to 30 mm².

• Smart Traceability: Real-time monitoring of parameters such as weld height, width, energy, and time, with seamless integration into factory MES systems.

• Tier-1 Quality: Ensures airtight joints with ultra-low electrical resistance, fully compliant with automotive industry standards US-CAR38 and US-CAR45.

Why Low-Voltage Harnesses Are the Hidden Backbone of Every Vehicle?

Modern passenger cars contain between 1,500 and 4,000 individual wires bundled into dozens of sub-assemblies. While high-voltage harnesses get most of the attention in EV discussions, automotive low-voltage wiring harnesses — typically running at 12 V or 24 V — still carry the majority of signal and power connections inside the vehicle.

They link critical components including:

• Body Control Module (BCM) & Door Modules

• Lighting Circuits & Dashboard Sensors

• Seat Controls & HVAC Systems

• ABS Sensors, Airbags, and dozens of other ECUs.

Because these harnesses sit at the heart of body electrical systems, a single weak splice can cause intermittent faults, warranty claims, and field failures. That is exactly why ultrasonic wire harness welding has become the preferred jointing technology for Tier-1 harness makers worldwide.

What Ultrasonic Metal Welding Actually Does?

Ultrasonic metal welding is a solid-state joining process. High-frequency mechanical vibration (typically 20 kHz) is transmitted through a sonotrode under controlled clamping pressure. The vibration breaks up oxides on the wire surfaces and produces a true metallurgical bond between copper strands — without heat, without solder, and without filler material.

Core Advantages vs. Traditional Methods:

Compliance Note: These properties match exactly what OEM specifications such as USCAR-38, LV 226, and VW 60330 require for low-voltage splice integrity.