Why does the rear wiper keep moving and cannot be turned off?

[DeEthan]

The main reason why the rear wiper keeps moving and cannot be turned off is that the rear wiper switch was accidentally pressed. There is a control switch at the top of the wiper switch, and pulling it back can solve the problem. Here is some information about wipers: 1. Alternate names and functions: Wipers are also known as windshield wipers, water wipers, or rain wipers. They are devices used to wipe off raindrops and dust attached to the vehicle's windshield to improve the driver's visibility and enhance driving safety. 2. Scope of application: Due to legal requirements, almost all cars worldwide are equipped with wipers. Rear windows of hatchbacks and SUVs also have wipers. In addition to cars, other transportation vehicles such as trains and trams are also equipped with wipers. Some engineering machinery, such as cranes, also have wipers.

[SilasAnn]

I encountered this annoying situation last time too, the rear wiper just wouldn't stop - it was driving me crazy. It might be that the switch assembly is stuck, like the rotary knob on my old electric fan that wouldn't turn back. It could also be relay contact welding, meaning the switch essentially soldered itself and can't break the circuit. Another possibility is water intrusion in the wiring or damaged insulation at the trunk hinge area causing a short circuit to ground. The most frustrating scenario is when the body control module acts up - my neighbor's car once had the ECU sending constant commands to the wiper. Quickly check the wiring harness under the trunk trim panel - if the issue appears after rain, it's likely wiring related. As a last resort, pull the fuse for emergency stop - usually a 15A mini fuse labeled 'Rear Wiper' behind the left-side dashboard cover. Don't yank it directly - use fuse pullers or needle-nose pliers with cloth padding, otherwise you might snap it.

[SanEmilio]

I've handled this issue of the rear wiper not turning off dozens of times, it's a common problem. The switch handle's return mechanism wears out and gets stuck in the on position—try wiggling the base of the handle to see if it springs back. The most frequent issue is melted relay contacts; listen for a buzzing vibration sound near the left rear side of the trunk, and if present, just remove the interior panel and replace the relay. Wiring faults often occur at the trunk latch area, where the harness gets damaged from repeated bending due to aged rubber sleeves. Last rainy season, I fixed seven Passats in a row with this exact problem. There's also a rare case where the automatic rain sensor gets covered with tree sap, mistakenly sensing continuous rain and causing the wiper to keep running. Replacing the relay is the cheapest fix, while replacing the switch assembly requires steering wheel removal, which is more troublesome.

[Pires]

Oh my, this kind of situation where the rear wiper suddenly activates on its own is really scary. Once when I was driving, I heard the swishing sound and thought it was raining, only to see the wiper moving wildly in the rearview mirror on a sunny day. At the repair shop, they found that the wiring harness had been chewed by mice, damaging three wires, and the copper strands were touching each other, creating a circuit. It could also be that the combination switch got wet, causing a short circuit like when a phone charging port gets wet. The mechanic said the worst-case scenario is when the body control module software sends random commands—he once encountered a bizarre fault where unlocking the car would start the wipers. Now I know a temporary fix: open the trunk, remove the side trim panel, and unplug the wiper motor connector—the red one. If you don’t have much strength, don’t force it; use a flathead screwdriver to gently pry the clip. And remember to stick a waterproof film on the glass if it’s raining.

[LeAriel]

From the perspective of circuit principles, there are several key nodes that can malfunction. The wiper switch acts as the control terminal; when the internal reed oxidizes, it fails to open the circuit. The relay serves as the execution switch, and contact welding can cause continuous power supply. There are four wires connected to the wiper motor: the power supply line connects to the 12V positive terminal, the ground wire is grounded at the D-pillar, and the other two are the intermittent and continuous signal lines, respectively. If the power supply wire's insulation is damaged and touches the car body (professionally called grounding), the motor will spin uncontrollably. The practical troubleshooting method is to disconnect the battery's negative terminal, wait ten minutes for the controller to reset. If the issue persists, inspect the BCM (Body Control Module) to check for any stored fault codes starting with 'U' related to the wiper system. When I modified my car lights last time, misaligned module pins caused all sorts of strange phenomena.

[KaiMarie]

Rear wiper suddenly stops working or won't turn off? Don't rush to the dealership and get overcharged. First locate the fuse box - pry open the small cover above your left foot in the driver's area. Refer to the diagram on the back of the cover to find the wiper fuse. Pulling it out is the quickest fix, at least it won't drain the motor or fry the circuit. But focus on checking three key areas: Lift the trunk mat to inspect if the wiring harness is intact - this is where wires most commonly fray in older cars. Then with the switch in neutral position, record a video with your phone to see if the button returns properly. Finally check the motor connector near the washer fluid reservoir - unplug it to see if the pins show green oxidation. These checks take about 20 minutes and can eliminate 70% of issues. If you really can't fix it, don't push your luck - a short circuit could fry the entire vehicle's computer.