How to wire rj-25 phone jacks

Written by raul avenir
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How to wire rj-25 phone jacks
(Jupiterimages/ Images)

An RJ-25 jack can accommodate three lines and has six colour-coded wires terminating in six copper pins. Special phones that can have three lines in a single telephone set are typically plugged into this type of telephone jack. A single phone having three lines saves space and is better than having three separate single-line phones sitting on top of your desk. You can learn how to wire an RJ-25 jack and improve your technical skills.

Skill level:

Things you need

  • Phillips screwdriver
  • Telephone cable stripper
  • Wire stripper
  • RJ-25 telephone jack
  • Three-line telephone set

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  1. 1

    Open the network interface device (NID) or telephone interface box outside your house. The NID is generally placed by your telephone company on a wall nearest to where their telephone wire runs from the utility post into your house. Unplug the modular connector inside in order to disconnect power from the main line and prevent a low-voltage shock while your working on your phone line.

  2. 2

    Pull the telephone cable gently out of the outlet box on the wall. Strip off 4 inches from the cable sheath using a pair of diagonal pliers or telephone cable stripper. Do not damage or nick any of the six inner wires. Strip off half an inch from the insulation of each coloured wire using a wire stripper.

  3. 3

    Get an RJ-25 jack and loosen all the terminal screws using a slotted screwdriver. Wrap each wire clockwise around its corresponding terminal screw and tighten each screw securely using the following scheme:

    --Green or white wire with blue stripes connects to the green terminal screw.

    --Red or blue wire with white stripes connects to the red screw.

    --Black or white wire with orange stripes connects to the black screw.

    --Yellow or orange wire with white stripes connects to the yellow screw.

    --Solid white or green wire with white stripes connects to the white screw.

    --Blue or white wire with green stripes connects to the blue screw.

  4. 4

    Fasten the faceplate onto the telephone outlet box on the wall with screws using a screwdriver. Reconnect the main phone line by re-plugging the modular connector inside the NID outside your house. Plug a three-line phone into the new RJ-25 jack. Press line one on the phone and listen for a dial tone. Press the other two lines consecutively and listen for a dial tone.

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