Automotive Wire Harness Connectors: 2.8mm, 6.3mm Faston and MX4.2mm Mini-Fit Selection Guide
Automotive wire harness connectors must withstand vibration, temperature extremes, moisture, and chemical exposure. This guide covers the most widely used automotive connector series from Yoeruyo with specifications and selection criteria for OEM manufacturers and vehicle electronics integrators.
2.8mm Faston Blade Terminals
The 2.8mm Faston blade terminal series is the standard for automotive signal circuits, relay coil connections, and low-power accessory circuits. Rated up to 15A, wire range AWG 22-16, operating temperature -40C to +105C. Used on ISO mini relays, fuse box connections, and low-current switch terminals throughout the vehicle.
6.3mm Faston Blade Terminals
The 6.3mm Faston blade terminal series is the standard for high-current automotive power circuits. Rated up to 30A, wire range AWG 18-12, operating temperature -40C to +105C. Used on ISO maxi relays, main fuse connections, battery disconnect switches, and alternator output terminals.
2.8mm vs 6.3mm Comparison
| Factor | 2.8mm Faston | 6.3mm Faston |
|---|---|---|
| Current rating | Up to 15A | Up to 30A |
| Wire gauge | AWG 22-16 | AWG 18-12 |
| Typical use | Signal, relay coil, low-power | Power relay, main fuse, high-current |
| ISO relay type | Mini relay signal coil | Maxi relay power contacts |
MX4.2mm Mini-Fit Compatible Connectors
The MX4.2mm (Molex Mini-Fit Jr. compatible) connector delivers 13A per contact at 600V UL in a dual-row format with positive latch and optional secondary lock. Used for ECU power, BCM power distribution, BMS wiring, DC-DC converters, EV/HEV auxiliary power, and ATX/EPS/PCIe PC power supply connectors.
L6 2mm Automotive Connectors
The L6 2mm automotive connector series provides compact vibration-resistant connections at 2mm pitch for sensor wiring and control module connections with positive-latch housing and secondary lock capability.
Insulated vs Non-Insulated Faston Terminals
| Type | Best For |
|---|---|
| Non-insulated | Production crimping with automated tooling |
| Insulated nylon sleeve | Field wiring and aftermarket installation |
| Fully insulated | Touch-safe and marine wiring |
Selection Guide
- Signal or low-power circuit: use 2.8mm Faston or L6 2mm
- High-current power circuit: use 6.3mm Faston or MX4.2mm Mini-Fit
- Select terminal rated at least 20% above maximum continuous current
- Match terminal wire range to your cable cross-section exactly
- Underhood or underbody: use sealed waterproof variants
- Vibration-prone or safety-critical: use positive-latch with secondary lock
Frequently Asked Questions
What is the difference between 2.8mm and 6.3mm Faston terminals?
2.8mm is rated up to 15A for signal circuits. 6.3mm is rated up to 30A for high-current power circuits. The two sizes are not interchangeable.
Are Faston terminals the same as spade terminals?
Yes. Faston is the original AMP/TE Connectivity brand name for the quick-disconnect blade terminal, also called spade terminal or tab terminal.
What is the MX4.2mm connector used for in automotive?
ECU power, body control modules, battery management systems, and EV/HEV auxiliary power distribution. Also the standard for ATX 24-pin and EPS 8-pin PC power supply connectors.
Do Faston terminals require a special crimp tool?
Yes. A ratcheting crimp tool with the correct die is required. Using pliers produces inconsistent crimps that fail automotive pull-out force requirements.
Can standard electronic connectors be used in automotive applications?
No. Standard connectors lack the vibration resistance, -40C to +125C temperature range, chemical resistance, and locking retention required for automotive use.
Conclusion
Yoeruyo supplies 2.8mm Faston terminals, 6.3mm Faston terminals, MX4.2mm Mini-Fit connectors, and L6 2mm automotive connectors with bulk and OEM pricing.
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