[GoinAllTheWay]

Spark plug? That's got nothing to do with your wipers.

So the motor that opeartes the wipers is working? If that is the case, what likley has happend is this. When you turn on your wipers, it fires up a small motor that is connected to a long arm and that arm slides back and forth, your wipers are connected to that arm. I would guess that the point where that motor attaches to the arm has popped off or something. Just get in there and do a visual on all the linkages, I'm sure you will find something has come loose. Depending on the year/model of car, it's pretty easy to fix. There should be some kind of grill right below your wipers that you can remove to see the linkages.

Just out of curiosity, did this happen after you had not used the wipers in sometime? What can happen is if your wipers go unused for a while, they can "stick" to the windshield and the next time you use them, the may not come unstuck very easily and the linkage suffers under the stress causing something to pop lose. Happened on one of my cars all the time.