Hi Mark,

A wire wrap tool is certainly not something expected to be found in a modern car repair facility, but you just might find one at a radio shack-- maybe.

You are right on about it being solid wire; I don't think the concept would apply to stranded, but I'm going to do some guessing here and say it was originally use by phone companies to eliminate soldering and unsoldering millions of wires in their wire centers. It later became the standard way to produce computer backplanes - both because it was so quick to make and remove for modifications.

A wire wrap advocate told me it is far better than printed circuit through-hole connections as each connection has "32 gas tight contacts" meaning that the solid wire is tightly wrapped around a square post 8 times. The wire is special to the task, in my example 30 gauge Kynar insulated. Just look at the pics of those failed fuel pump relays, etc. and you know exactly what he was talking about.

Nowadays the technique is mostly used for electronics prototyping-- a quick way to build something without making a printed circuit-- the connection is way to big physically to fit in modern day electronics packaging. So that's why I'm thinking it is possible radio shack doesn't have it any longer.

The tool is just a bit that fits over the square post, with a slot to accept the 30 gauge wire so you can tightly twist about an inch of it around the square post. Just a cheat to the soldering I'd have to do if I couldn't find the tool in my benchtop mess.

I googled up "wire wrap" and, as usual, learned something entirely new when 39,000 pages were returned. It also refers to a artist's technique used in jewelry making. Here's a major supplier of electronic wire wrap tools: OK Industries

Hope I haven't bored you to tears.

--
Art Benstein near Baltimore