An electrical connector housing system includes a plug housing, a receptacle housing, and a latching mechanism. The latching mechanism pivots on pivot posts on one housing and hooks to latching posts on the other housing, thereby securing the mated housings together. Catches on the latch mechanism engage with tabs near the latching posts when the latching mechanism is latched. The catches must be released using a screwdriver or similar tool before opening the latching mechanism and separating the mated housings. A protective barrier can be included to block direct access to the engaged catches and tabs. The housings include overlapping shells which exclude water and dirt, and the latching mechanism at least partially covers and further protects the shells when closed. In embodiments, a retaining mechanism automatically holds the latch open against gravity, facilitating connection and release of the housings with one hand and/or while wearing gloves.