What This Keying Plug Does
The 480143-1 is a keying plug that installs directly onto a contact position inside an AMP-LEAF series connector housing. Its job is to physically block a cavity so that the mating half cannot insert a terminal into that position, preventing miswiring or mismating in multi-circuit harness assemblies. The nylon body provides the dielectric isolation and mechanical retention needed for a permanent keying feature — once seated, it stays put through the life of the connector.