What it locks
The 174358-7 is the 3-position lock plate for TE's EconoSeal J Mark II 070 series — it secures the terminal position assurance (TPA) in the plug housing, preventing back-out under vibration. Molded in yellow, the plate snaps into the plug after the terminals are loaded and confirms each cavity is fully seated.
Which housing it fits
This lock plate is for use with EconoSeal Series J plug housings — the 3-position plate matches the 3-way plug body and retains the crimp terminals before the mating cycle.