Save up to 66% on your DIY electrical Wiring Project & get Material Lists, Instructions, Wiring Tips and more


Installing a Second Phone Line to an Existing Jack

June 18, 2006

Q: I just moved into a house that is wired for line 1 as the primary line in three different rooms. I had the phone company activate two phone lines, so I planned to simply rewire one of the jacks to line 2 as the primary line. I was able to get a dial tone when I rewired the jack to line 2 as the primary line. However, now the other jacks (still wired for line 1 as the the primary line) do not work. When I went back to red/green on the jack I had changed, the two other jacks work again.

What am I doing wrong that would wipe out Line 1 on the untouched jacks?

A: It sounds to me like your phone wiring is “daisy chained” from jack to jack. I believe that when you disconnected your existing primary line you opened a connection that went to the other jacks. To determine this, check to see how many phone cables come into the jack you are trying to rewire.

If there are 2 or more phone cables at that location, your phone wiring is “daisy chained”. If this is the case, I recommend taking the wires you had from your existing primary line and wirenutting them together color for color (red to red, green to green or blue to blue, white/blue to white/blue).

If you only have one phone cable at your jack, then it sounds like you may have shorted your existing primary line. If this is the case, I recommend capping the red and green or blue and white/blue individually. This will prevent the wires from shorting together.

Phone cable color code:

Line #1 Tip = Green (solid color twisted pair cable) or White/Blue (CAT5 cable)
Line #1 Ring = Red (solid color twisted pair cable) or Blue/White (CAT5 cable)

Line #2 Tip = Black (solid color twisted pair cable) or White/Orange (CAT5 cable)
Line #2 Ring = Yellow (solid color twisted pair cable) or Orange/White (CAT5 cable)

Line #3 Tip = White (solid color twisted pair cable) or White/Green (CAT5 cable)
Line #3 Ring = Blue (solid color twisted pair cable) or Green/White (CAT5 cable)

Line #4 Tip = White/Brown (CAT5 cable)
Line #4 Ring = Brown/White (CAT5 cable)

DIY Electrical Wiring Help from a Master Electrician Do you need assistance with your electrical wiring project? Please visit my DIY Electrical Wiring Help from a Master Electrician page. Where I provide electrical wiring tips, expert electrical advice, answers to your electrical questions and electrical consulting & design services over the phone, via instant messenger or via email.

If you enjoyed this post, make sure you subscribe to my RSS feed or receive updates via email. You can also follow me on Twitter and "LIKE" me on Facebook.

Similar Posts:
Site Sponsor


One Response to “Installing a Second Phone Line to an Existing Jack”

  1. Steven on August 2nd, 2006 11:46 pm

    I am having the phone company activate a second line on a phone jack, they told me I need to have this jack rewired. Could you explain to me how to do this?