What is the reason for the squeaking sound when car wipers scrape the glass?

[WilliamRose]

It may be an issue with the wiper blade itself, as it can become aged and hardened after prolonged use. Wiper System: The wiper system is driven by a motor, which converts the rotational motion of the motor into the reciprocating motion of the wiper arm (the part above the windshield other than the blade) through a linkage mechanism, thereby achieving the wiping action. Wiper Structure: The wiper assembly includes components such as a motor, reducer, four-bar linkage mechanism, wiper arm spindle, and wiper blade assembly. When the driver presses the wiper switch, the motor starts, and the motor's speed is converted into increased torque through a worm gear mechanism to drive the rocker arm. The rocker arm then drives the four-bar linkage mechanism, which in turn causes the shaft mounted on the front panel to swing left and right. Finally, the shaft drives the wiper blade to sweep across the windshield.