blue wire
n.
[IBM] Patch wires (esp. 30 AWG gauge) added to circuit boards at the factory to correct design or fabrication problems. Blue wire is not necessarily blue, the term describes function rather than color. These may be necessary if there hasn’t been time to design and qualify another board version. In Great Britain this can be bodge wire, after mainstream slang bodge for a clumsy improvisation or sloppy job of work. Compare purple wire, red wire, yellow wire, pink wire.