What is the reason for one wiper moving while the other remains stationary?
2 Answers
It may be due to a fault in the wiper motor's wiring. Here is some relevant information about wipers: 1. Working principle: When operating the wiper handle, the demand signal is transmitted to the BCM (Body Control Module), which then sends a start signal to the wiper motor. The wiper motor controls the wiper arm to perform the corresponding action. This is the working principle of the wiper. 2. Precautions: The wiring of the wiper's working principle differs from that of other electrical appliances. Other appliances turn off the positive pole (commonly known as the live wire), while the wiper wiring turns off the negative pole (commonly known as the ground wire or earth wire). This is why the wiper blade stops at the bottom of the windshield when the wiper switch is turned off at any position. Since the switch turns off the negative pole, if the wiper blade is turned off at another position, the C-shaped metal ring on the turbine inside the wiper assembly will still be connected to the car body, forming a working circuit. The wiper blade will continue to move until it reaches the opening of the C-shaped metal ring and stops.
I've driven several cars and encountered the issue of one wiper moving while the other doesn't several times. The most common cause is a broken wiper linkage mechanism. It's that metal rod or gear connecting the two wiper arms getting stuck or detached, causing one side to stop moving. You can check this yourself after parking: open the hood and try shaking the non-moving wiper arm by hand. If it feels stiff or makes a loose sound, it's almost certainly a mechanical issue. Another possibility is a problem with the wiper motor connection, where poor electrical contact affects only one side, or a fuse blowing on just one side. In older cars, insufficient lubrication causing rust in the bushing can also lead to this - sometimes adding lubricant like WD-40 can provide a temporary fix. In any case, don't take it lightly. Driving with impaired visibility during rain is extremely dangerous. Get it thoroughly checked at a repair shop as soon as possible, as compromising safety isn't worth the risk.
