Apropos of nothing, it's "jerry rigged". Jury-rigged is a corruption which is why it doesn't make sense. The phrase originates in World War 1 when jerry was slang for a German (and might itself have been a corruption of the word German).
Thanks, I actually always thought it was Jerry, but I see jury way more often and just had it in my head that I must have been wrong. :D The internet giveth and taketh.