Electrical Factors
Current Requirements: High current, low current, signal level; determines the terminal type, contact size, and plating (ranging from 0.64mm pins to 8.0mm male terminals); steady-state, cyclic, and transient conditions.
Wire Gauge/Insulation Requirements: Voltage drop and/or corrosion resistance; determines the connector pitch (centerline spacing).
Location/Environment
Temperature: Engine Compartment-sealed, ambient temperature > 105°C, vibration, fluid compatibility; Passenger Compartment-unsealed, ambient temperature < 85°C, where dimensional factors are primarily of greater importance.
Sealing: Potential exposure to high-pressure jets/splashes; potential for submersion; humidity; fluid types; for device-side connectors, whether the device itself is sealed.
Standards
Standards: Customer-specific standards; regulatory body standards; domestic standards; international standards.
Connector Performance Test Requirements: Included within system-level specifications; for General Motors, Ford, and Chrysler, these typically adhere to USCAR specifications (engine-related applications generally have higher vibration requirements); other OEMs typically maintain their own proprietary standards (similar to USCAR). Trend: Device-side suppliers are increasingly held responsible for the performance of the mating connector; since the device constitutes half of the board-to-connector interface, device suppliers are required to maintain excellent communication regarding the specifications and requirements of the mating connector.
Physical Factors
Size/Dimensions; Circuit Count; Mating Location; Wire Harness-to-Harness splicing or Device-to-Harness connection; Mechanical Assist Features: Levers, bolts; Manual Mating Capability; Multi-connector configurations for high I/O applications; Drawing/Documentation Requirements.
Assembly
Wire Harness: Connector insertion force requirements.
Operator Feedback: Visual, audible, and tactile confirmation of proper engagement.
Ergonomics.
High-Speed Manual Assembly Capability.
Reliable Assurance of Quality and Performance: Implementation of in-line testing and/or end-of-line processes; use of Terminal Position Assurance (TPA) and Connector Position Assurance (CPA) mechanisms; Serviceability/Repairability; Reduction in the number of loose components (a preference often prioritized in phased assembly processes).