A wiring unit for an electrical connector having a housing with a first side and an opposing second side, an attaching portion on the second side and a latching portion adjacent the attaching portion. The latching portion couples the wiring unit to a standard support. Electrical wiring terminals are coupled to the housing and can receive electrical wires. A stuffer cap is selectively coupled to the terminals and the attaching portion. When the stuffer cap is coupled to the attachment portion, attachment of the electrical wires to the terminals using an impact tool can be accomplished without damaging the latching portion since the stuffer cap spaces the latching portion from the support surface when the wires are forced into the terminals. When the stuffer cap is coupled to the terminals, the stuffer cap eliminates or substantially reduces oxidation or corrosion on the terminals and wires.