Synonyms for Haywire:

adj.

amiss (adjective)
awry.
flaky (adjective)
nutty.
haywire (adjective)
cracked, amiss, out of order, wacky, nuts, batty, insane.
on the blink (adjective)
bonkers.
on the fritz (adjective)
malfunctioning.

n.

haywire (noun)
daft, batty, loopy, barmy, kooky, loco, cracked, wacky, wrong, loony, round the bend, balmy, fruity, buggy, around the bend, out of order, bonkers, nuts, malfunctioning, whacky, amiss, kookie, nutty, dotty, the matter, insane, crackers, awry, bats, nonfunctional.

Other synonyms:

adj.
amiss, malfunctioning, out of order.