On Sep 27, 8:49*am, Bob Engelhardt wrote:
The fastest way to match-up ends of wires in a cable is a binary search.
* Where fastest means the least number of tests. *The number of tests
required is the number of bits needed to represent the number of wires.
* E.g. 64 wires would require 6 tests. *This is especially efficient
where each test means traveling some distance between the ends of the
wires. *I used it where I had a bunch of unmarked wires coming into a
fuse panel, the other ends of which went all over the house. *Each test
involved traveling the house, testing each end.

A binary search involves dividing the wires into 2 groups for each test,
then redividing them for the next test. *When you're done, each wire has
been in a unique collection of groups. *For example, say you have 8
wires, arbitrarily numbered 1 through 8. *For the 1st test, wires 1 - 4
are tied together (5-8 are loose). *In the next test 1-2,5-6 are (all)
tied & the 3rd test 1,3,5,7. *For each test, the tied-together wires are
rung to each of the loose wires on the other end. *So, if a other-end
wire rung to groups 1 & 3, it would be wire 3 (1-4, not 1-2, 1 or 3).

I could be more explicit, but you get the idea. *If you number and group
the wires right, the ring-ing groups are the binary number of the wire.

HTH,
Bob

BTW - it's "ringing out" cables, from the use a buzzer/bell to test
continuity.

That's a very efficient method when you have a way to jumper the wires
together in groups, but it doesn't work well for connectors if you
don't have spare mating pins.

I do the binary search a little differently to keep it simple. Connect
1+2+3+4 and check. If open I'd connect 5+6 and check. If open I'd try
7, then 8 just to confirm it. The number of tests is the same but
there's less handling damage to the wire ends.

I traced out my fuse box with a vacuum cleaner that makes a low rumble
which travels through the floors and frame of the house.

jsw