Match wire colors — Match each pigtail wire to the corresponding vehicle wire by color. Splice the wires — Use heat-shrink butt connectors for a waterproof, vibration-resistant connection. Insert one wire from each end and crimp. These connectors can be a big help when you need to connect two wires, repair damage, or extend a. Strip Insulation: Use wire strippers to expose 3/4 inch of bare metal on each wire's end, including the pigtail wire. Twist Wires: Use pliers to twist the stripped ends clockwise until they're. A pigtail, in its simplest form, is a short length of wire with a terminal or connector at one or both ends. For most residential 15-amp circuits, this means using.