An electrical connector 10, 100, 300, 800, 800', 900 comprising: an electrically-conductive spiral unit 14, 14', 14", 14"', 314, 814, 914 having a first portion 30, 116, 316, a second portion 40, 120, 320, and a longitudinal axis between said first portion 30, 116, 316 and said second portion 40, 120, 320, wherein the spiral unit 14, 14', 14", 14"', 314, 814, 914 coils around and defines an axial passageway, and, in a relaxed-configuration, has a relaxed internal diameter; and an electrically-insulating housing surrounding the spiral unit 14, 14', 14", 14"', 314, 814, 914 and comprising a first housing-portion 12, 121, 321, 812, 912 connected to the first portion 30, 116, 316 of the spiral unit, and a second housing-portion 44, 123, 323, 813, 813', 913 connected to the second portion 40, 120, 320 of the spiral unit; wherein said first housing-portion 12, 121, 321, 812, 912 comprises a first-housing-portion opening generally coaxial with and in communication with said axial passageway of the spiral unit, for receiving a first group of uninsulated wire ends 20 through said first-housing-portion opening and into said axial passageway of the spiral unit 14, 14', 14", 14"', 314, 814, 914 when the spiral unit is in the relaxed configuration; wherein said first housing-portion 12, 121, 321, 812, 912 and second housing-portion 44, 123, 323, 813, 813', 913 are rotatable relative to each other, on said longitudinal axis, to rotate said first portion 30, 116, 316 of the spiral unit relative to said second portion 40, 120, 320 of the spiral unit, to tighten said spiral unit into a tightened-configuration having a tightened internal diameter that is smaller than said relaxed internal diameter, for gripping and placing said first group of uninsulated wire ends 20 in electrical contact with each other and in electrical contact with said spiral unit 14, 14', 14", 14"', 314, 814, 914; and wherein the electrical connector 10, 100, 300, 800, 900 further comprises a first latch that retains the spiral unit 14, 14', 14", 14"', 314, 814, 914 in said tightened-configuration after relative rotation of the first housing portion 12, 121, 321, 812, 912 and the second housing-portion 44, 123, 323, 813, 813', 913. an electrically-conductive spiral unit 14, 14', 14", 14"', 314, 814, 914 having a first portion 30, 116, 316, a second portion 40, 120, 320, and a longitudinal axis between said first portion 30, 116, 316 and said second portion 40, 120, 320, wherein the spiral unit 14, 14', 14", 14"', 314, 814, 914 coils around and defines an axial passageway, and, in a relaxed-configuration, has a relaxed internal diameter; and an electrically-insulating housing surrounding the spiral unit 14, 14', 14", 14"', 314, 814, 914 and comprising a first housing-portion 12, 121, 321, 812, 912 connected to the first portion 30, 116, 316 of the spiral unit, and a second housing-portion 44, 123, 323, 813, 813', 913 connected to the second portion 40, 120, 320 of the spiral unit; wherein said first housing-portion 12, 121, 321, 812, 912 comprises a first-housing-portion opening generally coaxial with and in communication with said axial passageway of the spiral unit, for receiving a first group of uninsulated wire ends 20 through said first-housing-portion opening and into said axial passageway of the spiral unit 14, 14', 14", 14"', 314, 814, 914 when the spiral unit is in the relaxed configuration; wherein said first housing-portion 12, 121, 321, 812, 912 and second housing-portion 44, 123, 323, 813, 813', 913 are rotatable relative to each other, on said longitudinal axis, to rotate said first portion 30, 116, 316 of the spiral unit relative to said second portion 40, 120, 320 of the spiral unit, to tighten said spiral unit into a tightened-configuration having a tightened internal diameter that is smaller than said relaxed internal diameter, for gripping and placing said first group of uninsulated wire ends 20 in electrical contact with each other and in electrical contact with said spiral unit 14, 14', 14", 14"', 314, 814, 914; and wherein the electrical connector 10, 100, 300, 800, 900 further comprises a first latch that retains the spiral unit 14, 14', 14", 14"', 314, 814, 914 in said tightened-configuration after relative rotation of the first housing portion 12, 121, 321, 812, 912 and the second housing-portion 44, 123, 323, 813, 813', 913.