Buying pre-made telephone cables at a store may be fine for most applications, but if you need to wire many phones, or if you have long distances to cover with wire, it may be a good idea to make the phone cords yourself from bulk wire and plugs. It is relatively easy to crimp the plug onto the end of the wire, and this guide will describe how to wire a telephone plug correctly.
Strip about an inch of the sheathing from the telephone cable. This will expose a set of smaller wires. In older cords, these wires will be green, red, yellow, black, and sometimes there will also be a white and a blue wire. The red and black belong to the first line, the yellow and black to the second line, and the white and blue to the third line. Newer wire will include a white and blue pair, a white and green pair, and a white and orange pair.
Untwist the wires, but do not strip them, because the telephone plug will cut through the insulation to make a connection to the copper wire inside.
Orientate the phone plug so that the clip is on the bottom and the tip is pointing away from you. The pin on the left will now be pin number 1.
Line up the wires so that they will hit the correct pins when they are inserted into the plug. Pin 1 is used for the white wire in the older colour code, or the white with green stripe in the new code. Pin 2 is for the black or white with orange stripe. Pin 3 is for the red or the blue with white stripe. Pin 4 is for the green or white with blue stripe. Pin 5 is for the yellow or the orange with white stripe. Pin 6 is for the blue or the green with white stripe. In older wire, the white and blue wires may not be present, and will not be connected to the plug.
Cut the wires all to the same length, now that they are in the proper order.
Slide the wire into the plug carefully, ensuring that each wire runs into the correct pin slot.
Crimp the telephone plug to make the final connection. Telephone plug crimpers are available at hardware stores, and there are several inexpensive models from which to choose.
Test the cord to ensure that it works. Sometimes the plug will not crimp correctly, and in that case, the plug will need to be removed, and the entire process will need to be repeated.