Why Do Windshield Wipers Come On After Accidents?

Why Do Windshield Wipers Come On After Accidents?

Wiper blades play an important role in the overall safety of drivers. Their primary function is to improve and increase driving visibility, especially during harsh driving conditions, such as rain and snow. Wiper blades help to remove water, snow, debris, pollen, and dirt from the windshield, providing the drivers with clearer front and rear views.

That said, it’s safe to say that wiper blades are one of the few safety components of a car. One of the burning questions that people ask regarding windshield wipers is – why do they often come up after accidents? First, it’s worth noting that windshield wipers don’t always come up after accidents in every car.

Windshield wipers so sometimes come up after accidents. One of the reasons for that is probably because of the “inflation of the airbag.” As the airbag goes off, it hits the windshield wiper switch, turning it on. It could also be that the wiper was already turned on to wipe away the debris before the accident occurred.

What causes windshield wipers to come on by themselves? Why do windshield wipers come on after an accident? Can a bad windshield wiper cause a car crash?

What Causes Windshield Wipers To Come On By Themselves?

Why Do Windshield Wipers Come On After Accidents?

As you already know, wiper blades are designed to keep the windshield clean, providing you with a clear view while driving your car. They work by moving back and forth, removing water, dirt, debris, and other liquids from the windscreen.

Before going ahead to talk about why windshield wipers come on by themselves, let me quickly talk about the working principle of the devices. So, how exactly do wiper blades work?

Here’s How The Wiper Blades Work

For those who don’t know, the windshield wiper blades are operated by a combination of two different components; electric motor and worm gear. The motor is attached to the worm gear – a device used to transmit motion and power.

The worm gear is the component responsible for generating the necessary force, needed to keep the wiper arms in motion at various speeds. Other components that make the wiper blades work are the switch, control module, and relays.

Here’s how the wipers work; as you turn on the switch, the signal is immediately sent to the control module, which then operates the relay. The wiper relay works by sending the right power to the electric motor, which is connected to the worm gear.

That said, it’s safe to say that the wiper blades, in normal working conditions, can only work when you turn on the wiper switch.

Reasons Why Windshield Wiper Blades Come On By Themselves

There are several reasons why your vehicle’s windshield wiper blades can come on by themselves. Let’s have a quick look at some of them below:

  1. Is the wiper switch faulty or malfunctioning?

Your vehicle’s windshield wiper blades are probably coming on by themselves because the switch is faulty. The switch is often in use – this explains why it could malfunction over time. That said, the bottom line is that the malfunctioning switch could be the reason why the wiper blades are coming unexpectedly.

  1. Is the park switch faulty?

As earlier mentioned, one of the components that make the wiper blades work smoothly is the electric motor. Inside the motor, there’s a component called the park switch. The switch is the one responsible for allowing the motor to stop easily and quickly.

Furthermore, with a faulty park switch, an electric current can easily go through the wiper blades. Of course, this is irrespective of whether or not the wiper switch is on. If current flows through the wiper blades, it could trigger them on – this is another explanation for why your wipers are coming on by themselves.

  1. You probably have bad wiring

Bad wiring is another possible reason why your windshield wiper blades are coming on unexpectedly. If this happens, all you need to do is call on your technician to fix the issue for you.

Why Do Windshield Wipers Come On After An Accident?

Why Do Windshield Wipers Come On After Accidents?

Windshield wiper blades do not automatically and directly turn on (just like airbags) in response to an accident. 

Pressing The Wiper Switch

That said, if you notice that your wiper blades come on after an accident, it could be that your body has mistakenly pressed the wiper switch, turning it on.

Furthermore, as you already know, airbags will most likely be activated during an accident. As the airbag goes off, it could hit and turn the wiper switch on.

Bus-off State

According to Antonio Russo, a Quora user, another reason why the wipers come on after an accident is because of the “bus-off state” effect, which usually happens in modern vehicles when the accident is severe. In this case, the communication wiring that exists between several control units of your vehicle is damaged. This makes the control units “default to the condition that poses the least risk in a driving situation.”

Furthermore, when the ECUs move to default modes, lights, wiper blades, and some other components are switched on automatically.

Can Bad Windshield Wipers Cause A Car Crash?

Yes, bad windshield wipers can always cause a car crash. However, this will only happen if the windscreen is dirty, making you see less clearly when driving.

The wipers are designed to clean the windscreen and remove water, dirt, debris, and grime. However, in the case where the devices are not working and you’re driving in harsh weather conditions, the best thing to do is to avoid driving. That’s so because driving your vehicle in this situation could lead to an accident.

The bottom line is that “driving with bad windshield wiper blades”, especially during harsh driving conditions, can always cause a car crash.

Gui Hadlich

Hey there! I'm Gui. To be honest, I'm not really that interested in cars. But what I'm really, really not interest in is spending lots of money fixing my car up. Thankfully, I have a father-in-law who's obsessed with cars and a brother getting a PhD in internal combustion engines, so I get to learn about fixing cars. And with Fixing Engines, I hope to help you save a lot of money and take good care of your cars.

Recent Posts