To add a telephone line, run wires from the interface box outside to the terminal block inside, match some color-coded wires, and test for a dial tone. Moan faucet repair article.
Hooking up a phone can be easier than connecting speakers to a stereo because most homes have four-conductor phone wire running to one or more locations. Call your phone company and order the second phone line. You will then start this project by checking all the existing phone jacks for loose wires.
First some facts:
Phone lines are low voltage unless the line is ringing. Don’t hold both bare wires while having someone call your house.
Red and green are the most common colors used for older phone lines. Most old phone wire has four conductors (wires) of red, green, yellow and black. That will leave the black and yellow wire free for line two.
When purchasing phone wire, consider getting ‘twisted pair’ phone cable. It prevents interference from the other phone line and is much better for computer connections.
The decision for color matching from green and red on the old wire to blue and light-blue on the new wire isn’t critical. Most of the new wire will come in sets of a similar color. Blue and light-blue, orange and light-orange are common colors in new phone wire. Just choose one of the pairs for line one (your current phone number) and another for line two (the computer line).
Make an inexpensive tester using a phone jack, some wire, and two alligator clips. This will simplify testing and make troubleshooting easier. Purchase one extra phone jack and two alligator clips. Attach two wires of several feet in length to the red and green connectors on the phone jack. Then connect the alligator clips to the other end of the wire. Plug your phone in.
Now you have a test phone that can be clipped to wires here and there to check for a live line.
You’re ready to run some wires from the interface box, supplied by the phone company, into the basement close to the existing terminal block. When they install a new phone line they usually run the line to a gray interface box mounted to the house. Open the door, plug your phone in line two and check for a dial tone. Chances are only the new phone line is in this gray box. Your old phone line, if you are in an older home, probably runs directly into the basement to the old terminal block.
Note: To prevent a needless phone company charge, you should go here first if you ever have trouble with a phone connection.
In the gray box there are four screws marked red, green, yellow, and black. Hook two wires to the red and green screws and feed it into the basement to the old style terminal block. From here the existing phone wires run to the jacks in the house. If your house was wired with four-conductor wire your job is almost finished.
You should see all the green and red wires connected to two bolts on the block. These run your existing phones. There may also be black wires connected to the ground post. Once a prehistoric safety measure, these black wires are obsolete because the ground never gets hooked to any of today’s phones. They can be removed and twisted together. That should also leave some yellow wires just dangling around up there. Hook the black and yellow wires to the new wires from the interface box.
Wire all the blacks together with one of the incoming wires and the same with all of the yellows. Clip on the test phone and check for a dial tone. If it is clear and allows you to call your own phone you are good to go.
But if you have static or no dial tone there is probably a short at one of the jacks. Here the fun stuff begins. Disconnect one set of black and yellow wires from the group until a clear dial tone is heard. Follow the wires that are causing static to their respective locations and open those phone jacks. Check for wires that are shorted out or not spliced together. Make sure all the wires are connected to their matching color.
One problem I had was when a staple went into the phone cable and shorted out the black and yellow wires. It took forever to find that little problem.
At this point you can choose to install a single plug wall jack for each line. Simply connect line one wires to the “R” and “G” terminals and line two wires to the “B” and “Y” terminals. You will find these letters stamped next to the wire terminals on the back of the wall jack. You may wish to label the wall jacks line one or line two.