Automotive wiring harnesses and connectors form the backbone of a vehicle's electrical system. Without these components, the automotive circuit network would cease to exist. The testing of automotive wiring harnesses and connectors encompasses environmental, electrical, and mechanical performance evaluations, ensuring their quality, safety, and reliability—critical factors that directly impact the overall performance of a vehicle.
Failure Consequences:
- Signal transmission interruptions leading to functional device malfunctions
- Excessive contact resistance causing overheating or fire hazards
- Short circuits resulting in fire risks
- Insulation breakdown leading to electrical leakage
Testing Categories (Compiled by FAB Lab):
1. Inspection and Analysis Capabilities
- Visual/dimensional inspection
- Electrical performance testing
- Mechanical performance testing
- Environmental stress testing
- VOC and hazardous substance detection
- Electromagnetic compatibility (EMC) testing
- Cleanliness testing
- Metal/non-metal material analysis
- Failure analysis
2. Visual/Dimensional Inspection Parameters
- Surface roughness
- Profile parameters (roundness, cylindricity, line profile, surface profile)
- Geometric tolerances (parallelism, perpendicularity, angularity, coaxiality, symmetry, positional accuracy, circular runout, total runout)
- Axial/hole parameters (length, width, thickness, diameter)
3. Electrical Performance Testing
- Dielectric strength
- Insulation resistance
- Low-level contact resistance
- Shorting bar contact resistance
- Constant current contact resistance
- Voltage drop
- Transient electrical interruption
- Temperature rise
- Current-carrying capacity
- Current cycling
- LCR measurement
- Derating curves
- Conductor resistance
- Insulation volume resistivity
- Withstand voltage
4. Mechanical Performance Testing
- Terminal insertion/extraction forces
- Terminal bending resistance
- Housing insertion/retention forces
- Terminal normal force
- Connector mating/unmating forces
- CPA/TPA insertion/extraction forces
- Locking mechanism strength
- Structural integrity (fixation, assistance mechanisms)
- Anti-misinsertion features
- Seal retention
- Pin retention (PCB connectors)
- Trailer connector performance (insertion/extraction forces, locking strength, low-temperature shear strength, static load)
- Fretting corrosion resistance
- Mating cycles
- Audible mating confirmation
- Free/barrel drop testing
- Metal band retention (high-voltage connectors)
- Vibration/mechanical shock/combined environmental testing
- Connector mating durability
- Crimping cross-section analysis
- Cable stripping force
- Cable flexibility (low-temperature bending, impact, abrasion)
- Cable marking durability
- Crimp strength (terminal-to-wire)
- Insulation crimping bend test
5. Environmental Stress Testing
- Thermal cycling (high/low temperature, humidity, thermal shock, rapid temperature change)
- Corrosion resistance (salt spray, ammonia exposure)
- Chemical resistance
- IP rating verification
- Cable aging (ozone, thermal shock, long/short-term thermal aging)
- Seal integrity
- UV/xenon/ozone aging
- Mold resistance
- Pressure cooker test (HAST)
- Solderability/reflow sensitivity
- Liquid immersion testing
6. VOC & Hazardous Substance Testing
- ELV Compliance: Restricts hazardous substances in automotive materials:
- Hg, Cd, Pb, Cr(VI), PBB, PBDE ≤ 1000 ppm (0.1%) except exempted components
- Cd ≤ 100 ppm (0.01%)
7. Electromagnetic Compatibility (EMC)
- Conducted emissions (power/signal lines, time/frequency domain)
- Radiated emissions (antenna/TEM cell methods)
- Immunity testing (EFT, surge, RF injection, magnetic field)
- ESD testing
8. Cleanliness Testing
- Particulate contamination analysis per ISO 16232, VDA 19, PV 3370, and ISO 4406 standards, focusing on critical component areas.
9. Material Analysis
- Metals: Fractography, welding inspection, metallography, coating analysis, mechanical/corrosion testing, NDT
- Non-Metals: Mechanical/thermal/chemical/flammability testing, plastic electrical properties
10. Failure Analysis
- Post-failure diagnostics to identify root causes through:
- Decapsulation/sample preparation
- Cross-sectional microscopy
- SEM/EDS, TEM, FTIR, XRF, AES, XRD
- Dye-and-pry, thermal imaging
- FEA simulations
- Recommendations for design/process improvements to prevent recurrence
This rigorous testing framework ensures automotive wiring harnesses and connectors meet stringent reliability standards, safeguarding vehicle performance and occupant safety.
