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Anyone know about wiring phone lines?


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Hey -

So, we're making some renovations at our office, and have one standard four-wire phone line running from where our modem brings in phone/internet (via coax) and splits it to ethernet/wifi and two phone lines/cables.


I start by saying I'm generally competent, but know nothing about any of this - if my terminology seems weird, well, there you go :)


My business partner went to Lowe's and was sold four keystone connectors, and instructed to split the phone line with the red and green wires to one connect, and the yellow and black wires to the other, and then do the same again on the other end. The idea being that the two lines coming from the modem connect to those two jacks, and two phones connect to the other two jacks at the other end of the line.


Of course, this doesn't work. What did I do wrong or what should I do? I've been trying to find an explanation online, but most of it is related to CAT5 and ethernet and all that, or really old style phone terminals/jumpers.


Here's a pic of the connectors my partner bought - we have four (two for each end) and have one four-wire phone line running through the wall. Is there a way to wire this so there are two jacks at each end - one for each phone line?





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That looks like the back of an RJ-45 connector, 8 pin (Ethernet). A "regular" phone line has just 4 pins. You can certainly use Cat5 wire for you phone line and get 2 lines from the one run since it has 4 pair. You jack is probably jacked.

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It's been awhile but you want your computer(modem) signal coming in thru the Red/Green pair because it has twists in the wires. It has fewer per foot that Cat5. The Black/Yellow pair has no twists as I remember. They were primarily used to light the dial on "Princess" phones. Remember those? Anyway use the Blue/Blue-white terminals for the Red/Green wires and see if that works. Yellow-Black normally goes to Orange/Orange-white. There is a small plastic tool to seat the wires when pressing them in place. Good luck.

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Hey guys - thanks for the information. The pictured jack is a hybrid so it will work with either old style phone jacks (RJ11?) or CAT5 plugs - I just couldn't figure out the wires.


The info on the Blue and Blue/White Orange and Orange/White was spot on...but the crappy phone line my partner had purchased to run the extension had such tiny wires they didn't make good connections even with the proper push down tool... SOOO I decided to run a new, better cable, and to not have to mess with anything, I just ran TWO :) and then didn't have to mess with any wiring on other terminals.


thanks again -



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Bottom left corner pair in the picture.

Which are pin 4&5.

White Blue and Blue

Will work no matter if category A or B.



Now you just need to ID the active phone pair.

In Australia white and blue is the 1st pair and red and black is the 2nd pair.

If the same for you, one of the will be the active phone line. So just try one pair at a time until you get a dial tone.

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Thanks - that's very useful info for our next rewiring.


The guy at the home improvement store assured my partner that we needed to use the upper left pair for line one and the upper right for line two. That didn't work. I went home and got my voltmeter and eventually figured out which pins we did need to use (never did find a pinout map online that would show which pins on the back went to which pins on the actual jack/receptacle), but I was not able to use that connector to get a reliable signal through the wiring we had in place (I think the cheap four-wire phoneline extension my partner was sold had wires too thin to properly connect, but maybe I was using the connector incorrectly).


(In the US, on our old phone line color codes, line one was red and green, which are the center wires, and are now blue and blue/white; line two was the outside pair, which was yellow and black - i think now maybe that's orange and orange/white.)


Which is why I ended up running two new wires- probably could have figured it out if I'd had more time to play, but I had an appointment to get to that afternoon, and since we'd moved the front desk into the next room, I really wanted to get a couple of phone jacks in there so my admin/desk person could stop relying on the cordless handsets that aren't super great.



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(In the US, on our old phone line color codes, line one was red and green, which are the center wires, and are now blue and blue/white; line two was the outside pair, which was yellow and black - i think now maybe that's orange and orange/white.)


Yes, the Blue/Blue White is the center pair on an RJ-45 jack such as the one you show. However, the Green/ Green White goes to the next pair out on the RJ-45.


Just FYI.


Glad you got it sorted!

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