This electromechanical assembly consists of a motor, linkage, arms, and rubber blades designed to maintain driver visibility. The linkage converts the rotary motion of the wiper motor into a back-and-forth sweeping action. Proper blade tension and rubber condition are critical for streak-free operation and preventing glass scratches.
Heard on the job
The passenger side windscreen wiper is juddering on the downstroke, so check the arm tension and swap out the blade.
Insider tip
Wiper blades should be replaced frequently, but a quick wipe with rubbing alcohol can temporarily restore a streaky blade by removing oxidized rubber and road oils.