First, first find out which specifications of wiper blades your car uses, you can refer to the vehicle manual to see the wiper model indicated above. Generally speaking, wiper blades are sold with metal struts, and blades are rarely sold alone. If you are not sure, you can ask the clerk of the parts store to help you identify it.

Second, pay attention to whether the way the support rod is connected to the wiper rocker arm matches, because some support arms are fixed to the rocker arm with screws, so remember to pay attention when buying.

Third, pull up the wiper blade and touch the cleaned rubber wiper blade with your fingers to check for damage and the elasticity of the rubber blade. If the blade is aged, hardened, and cracked, the wiper blade is unqualified.

Fourth, during the test, place the wiper switch at various speed positions to check whether the wiper maintains a certain speed at different speeds. Especially in the intermittent working state, pay attention to whether the wiper blade maintains a certain speed when moving.

Fifth, check the state of the wiper, and whether the wiper rod has uneven swing or missed scraping. If the following three situations occur, the wiper blade is unqualified. The swing is not smooth, and the wiper bounces abnormally. The rubber contact surface and the glass surface cannot be completely attached, resulting in wipe residue. After wiping, the glass surface is in the state of water film, and fine stripes, fog and linear residues are produced on the glass.

Sixth, during the test, attention should be paid to whether the motor has abnormal noise. In particular, when the wiper motor hums and does not rotate, it indicates that the mechanical transmission part of the wiper is rusted or stuck. Immediately turn off the wiper switch to prevent burning the motor.