1. First, find out which type of windshield wiper your car is using, you can refer to the vehicle manual to see the wiper model indicated above.

2. Pay attention to whether the way the strut is connected to the wiper rocker’s arm matches. Because some of the arms are fixed to the rocker arm with screws, while others are locked with a lug.

3. Pull up the car wiper blades and run your finger over the cleaned rubber wiper to check for damage and the elasticity of the rubber blades. If the blades are aged, hardened, and cracked, the wiper is unqualified.

4. 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, it is also necessary to pay attention to whether the wiper maintains a certain speed during movement.

5. Check the wiper status and whether there is uneven swing or leakage of the wiper rod. If the following three situations occur, it means that the wiper is unqualified:

First, the swing amplitude is not smooth, and the wiper is not beating normally;

Second, the contact surface of the rubber and the glass surface cannot be completely fitted, resulting in wiping residue;

Third, the glass surface after wiping In the state of water film, fine streaks, fog and linear residues are produced on the glass.

6. During the test, pay attention to whether the motor has abnormal noise, especially when the wiper motor makes a "hum" sound and does not rotate. This means that the mechanical transmission part of the wiper is rusted or stuck, and the wiper switch should be turned off immediately to prevent the motor from being burned.

7. Some people think that the longer the wiper blade, the larger the brush area and the better the field of vision. In fact, the longer the wiper blade is, the better. Although lengthening the wiper blade length can increase the visible range of the field of vision, it will also increase the burden on the wiper motor and wiper lever. Of course, it is also possible to lengthen it, but it must not hinder the normal operation of the wiper.