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Replacing a Telephone Jack
By: Danny Lipford 
Is it difficult to replace an existing telephone jack? Does the electricity need to be turned off to replace it? -Sylvia
Hi Sylvia,
Replacing a phone jack in not difficult and typically just requires transferring the color coded wires from the old jack to the matching terminals on the new one. While telephone lines do have 48 volts of electricity running through them, it’s usually not enough to cause a shock, though it may affect a pacemaker.
The electricity in a phone line does spike to around 90 volts when the phone rings, which can give a mild shock. To prevent this from happening, unplug the modular jack at the telephone interface box where the line runs into your house, and check to be sure the phone is dead before working on it. Another option is to take a second phone off the hook to prevent it from ringing.
Since phone lines have their own source of electricity, they remain energized even when the power is off, so flipping the breakers to your house will not make any difference. Also, never work on the phone line during a thunderstorm since lightning can travel through the wire and result in serious injury.
For more information about working on telephone lines, check out our articles on:
Good luck with your project!
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23 Comments on “Replacing a Telephone Jack”
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September 11th, 2008 at 5:38 pm
I have a jack behind my desk that works but needed to plug in more lines i bought one of those plug ins that have three lines but plugs into the one jack thats behind my desk heres the problem the first two lines work and the last one doesnt whats going on here !1
October 13th, 2008 at 11:12 pm
ok my question is we just moved into a house and the phone jack does not work the wires from the outside that connect to the jack are not hooked up just wondering if anyone can help me out the color of wires that are loose is light blue, orange, white/blue, white/orange? i cant figure it out for the life of me thanks… nicole
November 11th, 2008 at 2:02 pm
I have a dual line telephone jack. The wires, from the wall, have detached. It is 2 pressure crimped, white with orange stripe. Where and how do I attach to the screws? Help…before I have to call the telephone company.
Ben Erickson Says:January 26th, 2009 at 9:56 am
Try looking in the outside interface telephone box to see what color wires are connected to the terminals, then use those wires to reconnect the wall jack. For more information, check out our article on How to Install a Phone Jack.
January 26th, 2009 at 9:50 am
My wife knocked off the telephone connector box for our upstairs phone while moving furniture. The telephone line going into the connector box was not color coded. It consisted of two wires with each one attached to a seperate terminal. The line from the telephone to the connector box was broken down to four wires being red, black, yellow and green. how can I make this work? Also, now my other phones don’t work
May 29th, 2009 at 11:06 pm
I have a constant busy signal on my home phone line. On my jack I have a splitter. One line goes to my modem and router with the other line going to my home phone. I’ve tried two brand new phones along with a new jack but still have a busy signal on the phone line line. The modem/router line works fine. Verizon installed the phone line. Later I switched to T-mobile. Both companies cannot help me. T-mobile states that they do not send out technicians to the home and Verizon states to call T-mobile for help.
Can you help me? I need a home phone badly.
thanks
July 24th, 2009 at 3:43 pm
Hi, i need help badly!! Okay i have a phone jack already installed but the box that that goes over the wires is not there and the wires don’t have anything to connect them to another phone jack. the wires are already there but they dont have nothing to connect them to another phone jack. Can you please help me!!!
Thanks
September 8th, 2009 at 6:17 pm
my phone just started to let me call out but no one can call in, phone doesn’t ring
October 25th, 2009 at 5:15 pm
I want to add a phone jack in a room that doesn’t have one. How do I attatch it the the wireing mess in the celler?
December 9th, 2009 at 8:03 pm
Question: My mom’s house has had the same jacks for 50 yrs none of the phones that have been replaced seem to work well, could the jacks just be to old, should they be replaced? First I thought it was the phones but I don’t think so…
Ben Erickson Says:December 10th, 2009 at 8:45 am
Jana,
Try plugging a phone in the jack on the outside interface box and see how the quality sounds from there. If it’s good, the problem is either in the wiring, connections, or jacks.
January 19th, 2010 at 3:49 pm
I need to know how to install a phone jack step by step. The wiring is already exposed form the baseboard.
January 21st, 2010 at 12:04 pm
I need to replace a phone jack, but when I detached the old jack/cover-there is a tangle of wires behind he wall that don’t seem to have any rhyme or reason? There is a thick white one, and then the typical red/green/yellow. I am afraid to
disconnect them for fear I will not be able to figure out the re-connect. HELP
May 19th, 2010 at 9:58 pm
I replaced a telephone wall jack (bedroom), and now one of the other jacks in the house (kitchen – the only other one that was plugged in at the time) doesn’t work. I tried another phone and got the same result, and also moved the kitchen phone from the non-working jack to a different one and it worked fine, so it’s definitely the jack itself. Any thoughts on this, did I knock out the kitchen jack when I replaced the bedroom jack?
In case it matters, my phone system is Verizon FiOS.
May 26th, 2010 at 8:45 am
I live in an apartment that was just remodeled on the inside. When they put up the drywall they covered all existing telephone and cable jacks. I had the cable company drill through the wall and create new ones, but I really don’t want to dish out the installation fee for a phone jack that I KNOW is there somewhere. How do I find where it was before they covered it so I can just install the jack on the inside myself? How can I tell where it is in my specific apartment from outside of my apartment?
Ben Erickson Says:May 27th, 2010 at 8:47 am
Hi Barbara,
That’s a tough one. I would start by approaching the manager of the apartment complex, since it should be there responsibility to fix it, and I imagine others there are having the same problem. If you don’t have any luck with management, here are some other things to try. If the phone jack was in a metal box, you might could find it using a stud finder. Also, check any before photos you might have taken of your apartment, see if it’s pictured, and try to estimate the distance from the floor and walls based on the size of other things in the photo. If you’ve got a general idea of where it was, the box was probably attached to a stud, so you could start from there, make a small hole in the wall, insert a small mirror with a flashlight reflect on it, or feel around in the wall for it. Your other option would be to run a new phone line.
June 6th, 2010 at 3:56 pm
I have a stainless wall mounted phone jack plate. I don’t want to mount a wall phone but would like some type of decorative cover to slip over the top. Could you advise where I might find this product?
January 11th, 2011 at 10:05 pm
The old phone outlet has been cut off.If the there are 4 wires (black,white,red,blue) in an older style single floor unit complex in Queensland. What coloured pair of wires would usually be used to put a single phone outlet on?
Cheers.
February 10th, 2011 at 5:17 pm
My phones go dead when they try to ring, I repaced junction box for bedroom answering machine they were a little corroded . checked all wiring in basement. phones had dial tone until they tried to ring. I had my son-in-law call back he said it rung once then nothing dead agan. all phones work from interface plug. any ideas?
Milt. P.S. I plugged into the interface box works from there.
December 30th, 2011 at 11:14 am
I have Fios. I am trying to replace a faulty phone jack, but when I went to unplug the phone following the guidance above, I found that I could not since the fios is all plugged in differently. I went to the fios box to see if I could unplug it there. No luck. Any ideas? Also, there seem to be the four colors on the new jack, but also a gray and blue/gray line.
thanks
March 13th, 2012 at 10:33 am
We have cable phone service. Recently, while remodeling my daughter’s bedroom, we unscrewed the old, unused phone jack from the wall, cut the wires from the jack, and taped them. We then installed a new blank panel, the same color as the other new outlets in the room, where the phone jack was. A couple of days later I noticed the fax and phone in my home office weren’t working, but the phone in the kitchen is fine. Since my home office and the remodeled bedroom are on the same side of the house, did we disrupt the circuit in some way? Or, is this coincidental?
April 2nd, 2012 at 9:14 am
my problem is this.. there are 6 telephone wires that come out of the wall. The telephone jack I bought has room for 4 wires and they are different colors than the wires coming out of the wall.. how do I connect the adapter?
April 11th, 2012 at 6:43 am
new phone and cable jacks were installed in my house 2 yrs ago. recently i pluged a phone into a phone jack and it does not work , it says no line. i disconnected the cover from the wall only to find that the green wire is not connected because it is too short, how can i fix this problem