Easy/cheap way for newb to find out which cable is which

Mister19stick

We refurbished our house, part of which was installing a home network. Long story short the project went tits up and the electrician is no longer contactable.

We're left with wired face plates in the rooms, but the other ends are just bare wires.

So, I'd like to determine which of the twelve wires sticking out of the wall links to which face plate.

Can you suggest a cheap and simple way of doing that?

mickevh

Yep:

Go to the remote end of each cable, if the ends are bare, strip the end of one pair of wires and twist them together (any pair will do, I'll use blue for illustration) then at the other end use a light bulb and a battery to test each lobe until you "find" the target. Label it, thence go back to the remote end and untwist and terminate. Rinse and repeat until all lobes labeled.

If your remote ends are already dressed onto the faceplates, then you can avoid de-wiring them by making up a "loopback" patch cord - ie an RJ45 plug with a short tail on it with the blue pair looped back as above. Then again proceed to test and label each cable lobe as above.

If you don't mind spending a bit of money, you can use one of the super-cheap ten pound cable testers which do more or less as above. They will require you to dress each lobe in the centre onto a patch panel or plug, but that should not be a big drama on a small number of cables, especially if there's a decent amount of "slack" on the cable ends.

"In the business" we have tools that you attach to one end of the cable that generates a "tone" on the wire, then there's a "wand" which you touch to the cables and when you hit the right one, it "squeaks." However, such things are probably not worth the expense for a "one off" job with relatively few cables.

If you wanted to be ultra-professional, you would uniquely label both ends of each cable lobe and record what goes where on a sheet of paper and lodge it in your network cabinet.

maf1970

A Quick check would be to see if anything was written on the cables at the bare end. Also are there numbers or letters on the face plates wired.
I am assuming you want to finish the project and that all the bare cables come back to one point then it may just be easier to get a patch panel and get all the cables connected up then figure out which one is which.

The Dude

I'd buy a cheap RJ45 tester and just punch everything down to a patch panel and see what goes where. If you're OCD about patch panel numbering you can always swap any that need moving. You need the cheap tester and the panel anyway, so no point wasting time trying to identify the cables.

The Dude

Worth pointing out too that if this is the handywork of an 'electrician' your wall outlets are probably wired up incorrectly, so don't be surprised if you end up doing those too.

mushii

You can buy a cheap cable toner on eBay for £30. Save yourself time and agro and buy one