how to fix my windwipers?

how can i fix my windwipers on my renault clio sport, they are not working at all and it is not the fuses as i have changed all of them, the back ones are working it is the front ones that have stopped, there is no noise or any thing to show that they are trying to work, i am worried that the power has gone but what would have stopped them from working, please could you give me some answers or some advice on how to fix them....