If a machine, a plan, or a person goes haywire, it suddenly stops working in a sensible way and starts going completely wrong — often in a messy burst, not a quiet little fault. English almost always wants the whole phrase go haywire, not haywire sitting alone. The word began as the cheap, springy wire used to tie hay. In New England logging camps around 1905, a haywire outfit meant a slap-dash set of tools, the kind of gear only held together with that wire and likely to fall apart. From there, to go haywire came to mean falling apart or behaving in a tangled, unpredictable way, like tight wire springing into a useless knot once you cut it. People now use it for printers, timetables, and tempers, not for farms.