Wiring an RJ12 Wall Socket - Wrong Wire Colours

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bhosking

4 posts

Wannabe Geek

#233266 7-Apr-2018 15:49

I have just moved into a new place and found that the wall jack has been unwired for some reason, although I am quite sure that previous tenants were using it for their modem to get internet.

Anyway I wanted to wire an RJ12 socket so that I can attach my modem but the existing wires seems to be the wrong colours to all information I can find on the subject, including the diagram that came with the socket.

Existing wiring is an 8-core with colours red, orange, green, black, white, grey.

There is also a 4-core with colours green, blue, brown, white.

I can't tell which wires were previously used. Does anyone have any ideas?

MattR

200 posts

Master Geek

#1991107 7-Apr-2018 15:58

If you're calling it an "RG12" socket, it is probably best you don't do it yourself. Do you have a photo?

bhosking

4 posts

Wannabe Geek

#1991118 7-Apr-2018 16:07

Yeah that's probably fair but I would appreciate some help anyway.

MattR

200 posts

Master Geek

#1991149 7-Apr-2018 17:09

You sure there was a phone socket there? looks like alarm cable.

bhosking

4 posts

Wannabe Geek

#1991150 7-Apr-2018 17:13

There was definitely a phone socket on the wall there when I moved in. When I got that off the wall there were no cables were connected to it.

I am about 95% sure that there was no alarm system previously.

I'm guessing there are no obvious solutions available?

sbiddle

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Biddle Corp

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#1991188 7-Apr-2018 18:07

The white and blue would be the phone - assuming the cable is connected at the other end. The other cable is an alarm cable.

People who wired that up clearly didn't know what they were doing anyway.

bhosking

4 posts

Wannabe Geek

#1991223 7-Apr-2018 18:38

Hopefully it is wired in at the other end because I think the previous tenants were using it at some point apparently.

So knowing that do you have any suggestions on how to wire it?

The plug has 6 pins so will it work with only four cores to get my internet up and running?

Any help would be appreciated.

MattR

200 posts

Master Geek

#1991239 7-Apr-2018 19:55

Yeah, if any of those are the phone line, it'll be the white & blue that is joined to the cable closest the power point. Each line is 2 wires, you'll want them in the middle two pins of the socket (don't put a plug onto that cable, put a socket on it). Again.. venturing into if you don't know, get somebody who does territory.

sbiddle

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#1991351 8-Apr-2018 09:37

I'm not actually sure where you'll find a RJ12 socket these days, they're pretty hard to come across even at wholesalers since they've basically been obsolete for 15 or so years as the RJ45 replaced them.

Unless you also want to buy a punchdown tool to insert the wires I'd recommend buying one of the tool less RJ45 sockets.

chevrolux

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#1991556 8-Apr-2018 17:59

Red/white is generally the first pair in an old six way cable.

So as others have, use that white/blue that has been jointed to the red/white.

The other cable isn't an alarm cable, just another six way.

InstallerUFB

833 posts

Ultimate Geek

#1991594 8-Apr-2018 18:24

You have basically two older phone cables (none are alarm type cable) - the one with 4 wires (red white blue & green ) - this would have been the original cable to the jackpoint - red & white would have been used for the circuit ( which has been extended out with the blue and white wires ( new colour scheme to match CAT cables )

The other is 6 wire (or 6way as it is known) (general arranged in 3 prs ) Red & white / blue & green / Black & orange

Judging from the crime kinks still in the wire ends - what was punched down on the jack point (BT socket) was the blue & white extended and the red & white of the 6way

This type of cabling (series wired) is not suitable to punch down on a RJ45 jack as the RJs (110) displacement crimps are only suitable for one wire - where as the displacements crimps (krone) you can punch down 2 to 3 (depending on wire gauge)

[I suspect that the power point has been altered or added as the phone cabling shouldnt be that exposed to the back of a power socket]