How To Install a Phone Jack

How To Install a Phone Jack

1. Strip the Outer Sheathing

   Strip 2 to 3 inches of the outer sheathing from the phone cable, using wire strippers. An old-style four-wire cable can be stripped using the 10-gauge slot on the wire strippers. Rotate the strippers as needed to cut all the way around the sheathing, being careful not to cut into the insulated wires inside the cable. Pull the cut piece of sheathing off of the end of the cable to expose the inner wires. 

   Alternatively, some phone cables have a pull cord inside that strips the sheathing as you pull back on it. In this case, start by stripping only a small amount of the sheathing using wire strippers, then use the pull cord to cut back the sheathing 2 to 3 inches. Trim off the portion of cut sheathing, using the cutters on the strippers or using cutting pliers.

2. Untwist and Strip the Individual Wires

   Untwist the individual wires inside the cable from one another. Strip 1/2 to 3/4 inch of insulation from each wire that you need, using the 20- or 22-gauge slot on the wire strippers. In many cases, you'll need to strip only two of the wires if you are installing a standard one-line residential phone line. A second pair of wires is used if you are installing a second line, such as a second voice-phone line. Often the phone wire or Cat 3-5 wire can be stripped by squeezing the individual wire's insulation with needle nose pliers and moving the pliers toward the end of the wire and the insulation comes right off.

   Then, identify the individual wires you'll be using:

   Old four-wire cable:

   • Line 1 (primary phone line): red and green
   • Line 2 (secondary line): black and yellow

   Cat-3 or Cat-5 cable: 

   • Line 1 (primary phone line): blue and white-with-blue-stripe 
   • Line 2 (secondary line): orange and white-with-orange-stripe

3. Install the Mounting Plate

   Remove the cover from the front of the phone jack, exposing the mounting plate and mounting screw holes. If the phone cable has been run inside the wall, thread it through the opening in the plate as you position the plate against the wall over the access hole. If the phone cable is surface-mounted, such as onto the front of a baseboard, the cable typically is inserted through a notch in the side of the phone jack. 

   Mount the plate to the wall, molding, or other structure, using a screwdriver and small wood screws or drywall screws. Some phone jacks may have self-adhesive strips for securing the plate to the wall, but if this type of jack also has screw openings, it is a good idea to reinforce the installation with screws. 

4. Connect the Wires

   Connect the stripped wires from the phone cable to the corresponding screw terminals on the jack. Use the following color combinations of wires that go together for a phone jack (each jack terminal is identified by the color of the wire that is preattached to it):

   Old four-wire cable: 

   • Line 1 (primary phone line): red wire to red terminal; green wire to green terminal
   • Line 2 (secondary line): black wire to black terminal; yellow wire to yellow terminal

   Cat-3 or Cat-5 cable: 

   • Line 1 (primary phone line): blue wire to red terminal; white-with-blue-stripe wire to green terminal
   • Line 2 (secondary line): orange wire to yellow terminal; white-with-orange-stripe wire to black terminal 

   To make the wire connections, loosen each terminal screw with a screwdriver. Wrap the bare copper end of the wire around the screw in a clockwise direction, using needle-nose pliers. Tighten the screw to secure the wire. The wire insulation should just touch the screw terminal and there should be no excess bare wire extending out from the screw.

5. Reinstall the Cover

   Reinstall the cover onto the jack's mounting plate. Some covers are secured with a screw; others simply snap into place. Plug a phone into the jack to make sure the line is working properly. 

How to Run Electrical Wires in a Finished Wall