Why does the wiper start by itself and cannot be turned off?

[McVincent]

If the wiper starts by itself and cannot be turned off, it is likely due to a fault in the wiper motor circuit. 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 then controls the movement of the wiper arm to perform the corresponding action. The wiper is a blade structure installed in front of the windshield, consisting of components such as the motor, reducer, four-bar linkage, wiper arm spindle, and wiper blade assembly. Its main function is to clear rain, snow, and dust from the windshield that obstruct the driver's view, improving visibility and enhancing driving safety. Rear windows of hatchbacks and SUVs are also equipped with wipers.

[DiLaura]

I've experienced the issue where the wipers turn on by themselves and can't be turned off. This is usually caused by an internal short circuit in the switch, possibly due to switch aging or water ingress causing contact adhesion, or the wiper relay getting stuck in the ON position. A short circuit to ground in the wiring is another common cause, such as wire wear or connector corrosion. Sometimes, a faulty body control module can send erroneous signals, causing the wipers to malfunction. It's recommended to first try turning the switch several times to see if it resets. If that doesn't work, pull the wiper fuse to temporarily stop them. This problem is especially dangerous in rainy weather as it can obstruct visibility and even cause accidents, so don't delay—visit a professional repair shop as soon as possible to check the wiring and components. When parking, always cover the wiper switch area to prevent dust and water from entering, which can help reduce such faults.

[OMia]

When the windshield wipers suddenly turn on by themselves and can't be turned off while driving, it can be quite frustrating. I experienced this myself recently. I suspected the switch button might be stuck or there could be a short circuit in the wiring. I tried toggling the switch repeatedly, but it didn't help. Later, I thought the fuse might be the issue, so I opened the fuse box under the hood, located the wiper fuse, and pulled it out—only then did the wipers stop. At the repair shop, the mechanic said the internal contacts in the switch were burnt out, and replacing the switch fixed the problem. This kind of issue is more common in older cars, as accumulated rainwater or dust can easily cause malfunctions. If this happens while you're driving, don't panic—first pull over safely to address it. Regularly cleaning around the switch can help prevent this problem.

[McJace]

It's really annoying when the windshield wipers turn on by themselves and won't stop. They keep swishing nonstop while driving, probably due to dust or water getting into the switch causing a short circuit. I've tried cleaning the surface of the switch, and sometimes it returns to normal. If that doesn't work, it might be due to aging wires short-circuiting, so check for any damaged wiring. Don't underestimate this issue—impaired visibility on the highway is very dangerous. It's recommended to visit a repair shop and let a technician test it with tools instead of disassembling it yourself. When washing the car, be careful not to spray water into the switch slot to reduce the chances of this happening.