An electrically conductive brush box is located against the upper surface of a base and has crimping tabs located against an oppositely disposed crimping surface. The base is formed of high temperature resistant plastic. A field case housing has a seat with a retention member adapted to retain the base against the seat. A screw is threaded into the field case housing such that the head presses against a surface of the base member to retain the base member in the seat. The screw member is located in non-contacting relationship with the electrically conductive brush box. A spacer member is adapted to space the portion of the crimping tab against the crimping surface away from the field case housing. The brush box includes a biasing member holder and the crimping tabs are located adjacent the holder.