The Molex 1718500500 is a 5-circuit, single-row receptacle housing from the Micro-Fit 3.0 171850 series. It uses the standard 3.00mm pitch that defines the Micro-Fit 3.0 interconnect family, giving you a compact but positive-locking wire-to-board or wire-to-wire connection. The black polyamide (nylon) body carries a Terminal Position Lock (TPA) feature, a secondary retention mechanism that locks each crimped terminal into its cavity after insertion. This prevents terminal push-back during mating or under cable strain — a common failure point in high-vibration harnesses. The wide span means the nylon housing retains its dimensional stability and latch retention through hot soak and cold start.
What the 3.00mm Pitch and TPA Mean for Your Harness
The 3.00mm pitch gives enough creepage distance between adjacent circuits to support the Micro-Fit 3.0 family's current rating (typically 5 A per circuit with the proper crimp terminal) without forcing an oversized connector footprint. For a 5-position single-row housing, the overall width stays under 20 mm, which fits neatly into space-constrained harness breakouts. The TPA (Terminal Position Lock) is the feature that separates a field-reliable connector from one that fails intermittently. After you crimp the female socket terminal and insert it into the housing, the TPA slides or snaps into place over the terminal's shoulder. This locks the terminal axially so that cable tug or vibration cannot push it back out of the cavity. If you are building harnesses for equipment that sees shock or continuous vibration, the TPA is not optional — it is the difference between a connection that stays mated and one that goes open mid-cycle.
Mating and Termination – What Goes with This Housing
This receptacle housing mates with any Micro-Fit 3.0 pin header that has the same 3.00mm pitch and the corresponding circuit count. For a 5-circuit wire-to-board connection, you would pair this housing with a 5-position Micro-Fit 3.0 vertical or right-angle header. The TPA then locks the terminal in place. This is a field-serviceable design: terminals can be removed with a proper extraction tool if a wire needs replacement.