what has gone wrong with my windshield wipers?

IF no movement at all..... It's most likely the wiper 'transmission' that's giving the problem. The part that hooks up to the wiper motor. Needs to be inspected to be sure!

If you hear the motor , then the linkage needs to be inspected for where the failed part(s) are. Depending on parts availability , you could get away with just replacing the two links , rather than the whole 'transmission. Either way , about 1 hour labor (whatever the rate is in your area) and I would check the Honda dealer for link availability , I'm not sure if they'd be available by themselves aftermarket(never checked). Usually a good flashlight and eyes(better than mine) will be able to tell , without removing the cowl, although , for the repair , it all needs to come out anyway. Hope this helps a little. Any more questions , please ask.