Since its a silicone-based product that sits on top of the glass, it does come off over time and can end up on the wiper blade affecting performance. There is an alternative to rainx on the market called Trico View (formerly Aquapel) that actually bonds to the glass and thus doesn't come off the glass and onto the wiper blades. See related link below.
If it's plastic it may be damaged.
Windshield wipers don't work
Why are there windshield wipers inside the car?
they could be old and cracked.if their new they may not be slick enough,buy a can of rainx it should fix it. I remember getting a "factory recall notice" about the wipers (which I did not take advantage of) and have the same problem occasionally. I am planning on replacing the wiper motor.
Replace the windshield wipers.
Mary Anderson invented windshield wipers in 1903.
When purchasing windshield wipers that work intermittently, they can be any windshield wipers that are the correct size. The ability to work intermittently is a wiring/fuse ordeal. This does not play a part in the selection of windshield wipers that you choose from.
The windshield wipers go back in forth if you now now what i mean
A bad relay switch will cause the windshield wipers to not turn off. Replace the relay switch and the windshield wipers should turn off.
replaceing windshield wipers toyota truck
You do not want to have wipers that extend off the edge of the glass - it hinders the performance of the wipers, shortens the life of the wiper and can create stress and damage to the wiper arms, wiper linkage and wiper motors.
does a sub marine have windshield wipers