An electrical connector includes a window assembly including an electrically insulating transparent base and a plurality of electrically insulating transparent windows extending outwardly therefrom. The connector may include an electrically conducting body having spaced apart cable-receiving passageways for receiving respective insulation-free electrical cable ends therein, and with each cable-receiving passageway having a cable inlet opening and a cable end viewing opening opposite the cable inlet opening. The body may also have at least one respective fastener-receiving passageway intersecting each cable-receiving passageway. The individual windows of the window assembly are aligned with respective cable end viewing openings to provide a cover and to permit visual confirmation of proper placement of the insulation-free electrical cable end within a corresponding one of the cable-receiving passageways. The connector may further include an insulating cover on the body and defining a seal with the window assembly.