How to Wire USB Cables

usb image by Richard villalon from

USB cables replaced the old-fashioned serial and parallel ports that used to connect peripherals to computers. This standardisation of technology allowed more manufacturers of computer peripherals to connect to a variety of other systems, giving the user more choice in peripherals.

It also makes it possible to wire USB cables in the home workshop, saving money. The three types of USB connections--A, B, or mini--are all wired in similar ways. Master one, and any can be done.

Pry open the cover on the jack and plug connector. Insert the tip of a mini flathead screwdriver in the breakline on the flat side of the case, and push upward. The breakline is the break in the case where the cover meets the body.

Strip 1/4 inch of insulation off both ends of each wire you will be using. Every type of USB connector requires four wires to be installed. It is advisable to use a red wire for the power source, white for the data wire, green for the wire that will carry data input, and black for the ground wire. The colour only refers to the insulating coating around the wires. Standard use of colours will make future repairs easier.

Lay the wires into the channels inside the case. Use one wire per channel, with the bare ends of the wire placed so they are touching the metal plates at the end of each channel.

From left to right, the wires should be installed in the following order for USB A connectors: red, white, green and black. This order also applies to mini USB A and mini USB B jack connectors, except you can skip the fourth channel when placing the wires.

USB B jack connectors have two rows of channels. The wires for this connector also should be placed in order. The top row, from left to right, should have the red wire and then the white wire. The second (or bottom) row, from left to right, should have the black wire and then the green wire.

Repeat these steps to wire USB plug connectors. USB B plug connectors require that the wires are placed in the following sequence from left to right: for the top row, place the white wire and then the red wire; for the bottom row, place the black wire and then the green wire.

Press the covers closed on the plug and jack cases to finish connecting the wires. The covers will snap into place.