> 1986 Audi 5000 Turbo Transaxle (FWD). I traced the wires right to the diff, but not sure exactly what they do. I tested with an ohm meter to see if they open/close when the diff rotates, but that wasn't it... the two wires held a constant 175 ohm reading. Maybe its a light bulb :) > Could you have found the reverse light switch? - Dave