Tracing a Cat5 cable used for telephone connection back to 66 block

Question

I have a Cat 5 ethernet cable terminated with a RJ45 Ethernet (8P8C) jack in the Master BR that is serving as a telephone connection. The other end of the cable is punched down into a 66 Block in the basement. This was a part of a structured wiring setup from year 2000.

Now I want to re-purpose that Cat 5 cable to serve as an Internet data connection. I want to find the other end of this cable in the 66 block so I can connect it to my internet network. Once identified, I will terminate that end with a RJ45 connector.

I have used a Klein Tools Tone Generator and Probe with the RJ45 connector inserted into the RJ45 jack in the Master BR, however every Cat5 cable in the house that serves my other phone jacks tied into the 66 Block are getting the tone. The tone is also heard through the phones. The tone generator is set to "tone".

How can I trace and isolate this single Cat5 cable without getting tones from the other cables?

Answer 1

My assumption is that all the jacks in your house are connected together at the 66 block for analog voice. You had one analog phone line coming into the house, and all jacks with a phone plugged in would ring at the same time. Very standard when wired for voice. At least you have all the jacks installed as home runs back to one place instead of connected in a long daisy-chain! That makes the cables possible to repurpose for Ethernet.

In order to figure out which cable coming into the 66 block is the one you are sending the tone on, you'll need to isolate the house cables from each other. The best way to do that at the 66 block will depend on how they are connected. I've done them with bridge clips and with hookup-wire jumpers. Bridge clips will be easy to see because they are big metal clips that connect two contacts in the block. Pulling them out with pliers is easy. Hookup-wire jumpers are a little more difficult to pull off, but not too bad, especially if you have needle-nose pliers.

If you can include a picture of the back of the RJ-45 jack/plate and a picture of the punchdown block, we can zero in better on how to get this done.

When putting these into use as Ethernet jacks, you'll want to terminate each cable with an individual keystone jack that can either hang free or click into a small patch panel. They even have 12-jack patch panels that click into the same mounting bracket your 66 block is in now, if you want a clean look.

Update

Now that we can see the blocks, we can see what is going on.

The yellow cables are presumably your house wiring. The blue ones are presumably cables that come in from a network interface outside the house (where the Telco service comes in).

Each cable is punched down to the outer "hooks" of the 66 block, pair by pair. The Blue/white is default for "line 1" when used for voice. Each set of 2 "hooks" in horizontal line are connected together inside the block, thus to cross connect to your jumper wire, you'd punch it down to the inner matching "hook".

Unless you're really dedicated to maintaining this wire and own a 66 punchdown tool, I'd suggest pulling the yellow "house" cables off the blocks and reterminating them with 8P8C jacks. It's just much easier to deal with unless you really want to pretend you work for Ma Bell. :)

Answer 2

If you'd rather not undo your phone setup (might be desired if it's still in use for a landline) you can connect to one of the unused pairs in the cable of interest, assuming the typical voice on 4,5 blue/white setup, other pairs not punched into anything.

Either strip the ends and clip on to a different pair, if your toner does that, or pull the blue-white pair from the one jack you want and punch in one of the other pairs (or all of the other pairs) and connect your toner. I've done it with a 9V battery connected to the pair of interest and a voltmeter, in the absence of a toner.

I'm making usual assumptions (house is not wired for multiple phone lines, standard use of colored pairs, etc.) which could be subject to revision if you post pictures of what you actually have. You may need to upgrade the old 8P8C jacks to 5e or better for fastest ethernet speed you can get from the cable you have (it might do gigabit, even though it's only 5. But older jacks might limit it to slower speeds.)

Edit, Add: Now that we can see pictures, it looks like whoever put this in punched down everything. However, the green and brown pairs are not interconnected so you should still be able to track down the cable you want without disturbing your remaining analog phone line.

If your tone tester has alligator clips, (most pictures for that tool description show a set) clip them on the 66 block where a green or brown pair attaches, [so one to the green (or brown), one to the white-with-green (or white with brown) right next to it] and then find the cable they go with in the house. Update/improve/clarify the labeling if it does not seem to match what's there. I'd expect one of the ones labeled MBR would be your best bet for the master bed room. That way you don't have to mess about with disconnecting wires at the far end, nor tearing up your extant analog telephone wiring that's still in use.

The wiring to the jack will, at minimum, need to be removed, have the twist restored, and be reconnected, even if that is a 5e jack (which it isn't, being from 2000 - so get some 5e or better jacks.)