I have a 89 Mercedes and a few days ago the wiper blades stopped working as well as the windows. They were iced over and I cleaned off the ice and tried again the next day. There is no sound when turning things on. I also tried the windshield washer fluid and nothing happened.
It's still very cold and I think the arm may be up a few inches rather than in its start position but I would have to check again.
As Bob mentioned in the comments the problem was the fuse was blown. I replaced the fuse and everything is working again. On a side note, another fuse was blown and after replacing that the sunroof is working again.
BTW For future reference the fuses are special fuses (not sure if they are special or not) in that I had to get them at an auto store. You can look online, for example Amazon, and give it your make and model and it will describe the type of fuses you need.
My immediate answer is to check the fuses 1st as many times the strain from a motor struggling to work can and will overload a fuse circuit and the fuse blows rather than start an overheat fire. As a rule, I always take my volt tester light and test every fuse not just the ones I show as the likely fuse simply because you never know what you might find blown while there and generally it may resolve an issue you weren't aware existed. You might try also if the fuse isn't the issue to give a little pull on the arm in cases the motor has a dead spot in the armature. I've also seen the soft metal gear connecting the arm to the shaft strip completely out and the motor is spinning inside the arm though you would hear it is running on this case.