Cleaning
If the washer fluid fails to clean the windshield of your vehicle, or if one of the wiper blades does not work properly, wax or other materials may have built up on the wiper blade or on the windshield.
Clean the outside of the windshield with washer fluid or a mild detergent. The windshield is clean if water does not bead up when you rinse it with clean water.
Clean each wiper blade with a cloth soaked in washer fluid or mild detergent. Then rinse the wiper blades with clean water. If the windshield is still not clean satisfactorily after cleaning the blades and operating the wipers, replace the blades.
WARNING
Worn wiper blades can damage the windshield and impair the driver's visibility.
Test yourself
A quick Nissan Altima quiz: every answer comes with an explanation and a link to the manual page.