The situation when the wiper is broken, most often takes the driver by surprise during heavy rain or snow, turning the trip into a dangerous test of attentiveness. The lack of a clean windshield critically reduces visibility, and attempts to drive “at random” can lead to a serious accident. In such conditions, it is necessary to quickly diagnose the malfunction and, if possible, fix it on site or drive to the garage with minimal risk.
The reasons for windshield wiper failure can be trivial, such as a broken rod, or more complex, associated with a burnt out winding. electric motor. Understanding the principle of operation of the mechanism allows the driver to independently carry out initial diagnostics and determine whether a complete replacement of the unit is required or a simple repair is sufficient. In this article we will look at the main breakdowns and how to fix them.
Before starting disassembly, it is important to assess the nature of the breakdown: have the wipers stopped moving at all, work only at one speed, or are they making an extraneous hum? The algorithm for your further actions depends on this. If the wipers are stuck in the middle of the glass and do not respond to the button, first check the fuse in the mounting block.
Diagnostics of electrical circuit and fuses
The very first step to take if wipers don't work - This is a check of the integrity of the electrical circuit. Often the problem lies not in the mechanism itself, but in a banal blown fuse that protects the circuit from overloads. Find a diagram of the mounting block in your vehicle's owner's manual and locate the element responsible for the windshield wiper (usually designated as WIPER or the wiper symbol).
Visually inspect the removed fuse: if the thread inside is burned out or the body is blackened, the element requires replacement. It is important to install a fuse strictly of the same amperage rating as specified by the manufacturer to avoid repeated burnout or, worse, fire of the wiring. If after replacement the situation repeats, it means that there is a short circuit in the circuit, and the troubleshooting must be continued deeper.
It is also worth checking the windshield wiper relay, which is responsible for intermittent operation and returning the blades to the parking position. A faulty relay can cause chaotic brush movements or complete system failure. In some modern car models, such as Volkswagen or Toyota, control can be carried out through the electronic body control module (BCM), which requires computer diagnostics.
⚠️ Attention: Before replacing fuses or carrying out work on electrical wiring, be sure to disconnect the negative terminal of the battery to avoid short circuits.
Mechanical faults: trapezoid and rods
If the electrical part is OK, but wipers don't work or move with difficulty, the problem most likely lies in the mechanics. The main element here is the trapezoid - a system of levers and rods that transmits force from the motor to the brushes. Over time, the lubricant dries out in the hinge joints of the trapezoid, dirt and oxides accumulate, which leads to jamming of the mechanism.
A common failure is the rods falling out of the plastic bushings or their breakage. In this case, the motor may hum, trying to turn the mechanism, but there will be no movement of the brushes, or one of the brushes will work, and the second will stand still. For diagnostics, it is necessary to remove the decorative plastic trim (frill) under the windshield and visually inspect the condition of the levers.
Restoring the mobility of the trapezoid requires its dismantling, complete disassembly into its components, cleaning of old grease and applying new, frost-resistant grease (for example, lithium). If cracks are found on metal levers or broken plastic bushings, repair or replacement of the entire assembly will be required. On cars with high mileage, the metal of the trapezoid may become tired and deformed.
Repair and replacement of windshield wiper motor
When the mechanical part is free, but the wipers are still don't turn on, (suspicion) falls on the electric motor. The windshield wiper motor is a complex assembly consisting of the motor itself and a built-in gearbox. A characteristic sign of a motor malfunction is a quiet hum when turned on or a complete lack of response, despite the presence of voltage at the contacts.
Inside the motor, the commutator brushes may wear out, the contact group may become dirty, or the parking limit switch may fail. The limit switch is responsible for ensuring that the brushes return to their original position at the bottom edge of the glass after turning off. If it is faulty, the wipers may stop anywhere on the windshield, blocking your view.
Repairing a motor is often impractical due to the difficulty of restoring the tightness of the housing and selecting components. It is easier and more reliable to replace the entire assembly. When installing a new motor, it is important to set its position correctly so that the stroke of the brushes corresponds to the factory parameters and they do not touch each other or the body.
☑️ Motor diagnostics
⚠️ Attention: When installing a new motor, make sure that the trapeze is in the parking position, otherwise the mechanism may fold or damage the rods when first turned on.
Replacing brushes and frame elements
Sometimes the problem is not that the mechanism is broken, but that the consumables are worn out. Windshield wiper blades are a consumable item that require regular replacement, usually once a year or when streaks appear on the glass. If wipers don't work wellleaving rainbow streaks or uncleaned areas, replace the rubber cleaning bands or brush assemblies.
There are three main types of brushes: frame, frameless and hybrid. Frame ones are cheaper, but they become covered with ice faster in winter. Frameless ones fit tightly to the curved glass of modern cars, while hybrid ones combine the advantages of both types. When choosing, pay attention to the type of fastening (hook, button, bayonet), as they are not always universal.
Do not forget also about the condition of the leashes themselves (the levers that press the brush). The spring inside the leash weakens over time, and the brush no longer fits tightly to the glass, especially at high speeds or with oncoming air flow. If the spring is weakened, you can carefully tighten it or replace the entire leash.
| Fault type | Probable Cause | Solution | Difficulty |
|---|---|---|---|
| The wipers don't move | Fuse or motor burnt out | Replacing the fuse/motor | Low |
| Moving slowly | Trapezoid soured | Lubrication or replacement of trapezoid | Average |
| Stop in the middle | Limit switch faulty | Motor repair or replacement | High |
| Grinding and vibration | Worn bushings or brushes | Replacing bushings/liquor | Average |
Seasonal problems: what to do in winter
In winter there is a risk that the wiper breaks, increases many times over. The main reason is the freezing of the blades to the windshield or the accumulation of snow mass in the mechanism. Trying to turn on frozen wipers is almost guaranteed to result in a fuse burning out, gearbox teeth breaking, or trapezoid rods stretching.
Before turning on the windshield wipers in winter, be sure to warm up the interior and make sure that the rubber band of the blades is clear of ice. If the brushes are frozen, do not pull them by force - use a glass defroster or warm (not boiling water!) water. It is also recommended to raise the wiper arms up when parking at night so that they do not freeze to the glass.
Another winter problem is snow filling the frill (the space under the wipers). The snow there melts from the heat of the engine, turns into water, and freezes at night, blocking the movement of the trapezoid. Regularly clear the area of snow before parking the vehicle.
Prevention and care of the cleaning system
In order for the question “how to fix wipers” to arise as rarely as possible, the system requires regular maintenance. At least once a year it is recommended to remove the brushes and lubricate the trapezoid hinges. It is also worth checking the tension of the springs of the leads and the cleanliness of the glass surface, since dirt on the glass acts as an abrasive, accelerating the wear of the rubber bands.
Use high-quality antifreeze fluid. Cheap anti-freeze products often contain aggressive components that destroy the rubber elements of the brushes and the paintwork of the body. In addition, they can leave a greasy film that is difficult to wash off.
Monitor the operation of the washer nozzles. If they are clogged, you run the risk of rubbing a dry wiper on dry glass, trying to remove dirt, which will instantly damage the working edge of the blade. Clean the injector holes with a fine needle if necessary.
Frequently asked questions (FAQ)
Why do the wipers only work at one speed?
This indicates a malfunction of the mode switch (steering column stalk) or the combustion of one of the windings/contacts inside the motor responsible for the second speed. There could also be a problem with the relay.
Is it possible to drive if the wiper is broken?
According to traffic regulations in many countries, driving with faulty windshield wipers in rain or snow is prohibited. This is life-threatening. You can only drive to the repair site or garage, using extreme caution and minimum speed.
How to remove jammed wipers if they won't park?
You need to remove the motor from the trapezoid (usually 3 bolts), turn on the ignition and the wiper button so that the motor shaft rotates, then turn it off. After this, you can manually set the trapeze to the desired position and install the motor back.
What is the service life of the windshield wiper motor?
On average, a motor lasts from 50 to 100 thousand kilometers, but it greatly depends on operating conditions. Frequent use in winter with a load of ice reduces the service life significantly.