What This Plug Does on the Harness
The TE Connectivity MTA-156 3-641438-9 is a 9-position IDC plug that mass-terminates 24 AWG discrete or ribbon cable in one press operation — no individual crimp terminals, no loose contacts to feed. The 0.156" (3.96mm) pitch matches the standard MTA-156 header footprint, so the board layout is fixed once you pick this series. Tin plating on the male pins (80.0µin thick) handles a few mating cycles in a permanent harness install; it's not a high-cycle gold contact, but for a set-and-forget wire-to-board connection the tin saves cost over the gold-plated siblings. The closed-end housing stops the wire from poking out the back, keeping the harness profile clean and avoiding a short against a metal panel or enclosure wall.
IDC Termination — One Press, No Loose Parts
This plug uses insulation-displacement contacts: the wire sits in the slot, and the press tool forces the insulation aside so the tin-plated male pin bites into the conductor. No stripping, no crimping, no loose terminal inventory — the whole 9-position cable end terminates in one stroke. The wire gauge is locked to 24 AWG; the IDC slot geometry won't grip 22 AWG reliably, and 26 AWG may pull out under tension. Discrete or ribbon cable both work, but ribbon needs a slit at the breakout if you're daisy-chaining. The closed-end feature means the wire stops inside the housing — no tail to trim, no risk of a stray strand touching the header pins on the back side.
Mating and Mounting — Free-Hanging Right-Angle
The tin-on-tin contact interface is fine for a few mate-unmate cycles during assembly or field service; beyond that, the tin frets and contact resistance drifts. For a harness that stays mated for the life of the equipment, this is the right call. The white housing colour is the standard MTA-156 natural; no keying or colour coding on this variant.