Get yourself a circuit tester!.. multimeters can be confuseing, if your not entirely sure what your doing..
A circiut tester consists of a pointed probe with a bulb in it, a legnth of wire and a crocodile clip.. earth the clip, and probe your wiper plug to find a live, remember that you must have the wiper/ignition swithed ON to find your live! also, test your fusebox with this peice of kit
My money is still on that you have a broken wire!
Tom