A wiper that leaves one fine line usually has a different fault from one that smears a greasy film across the glass. When wipers stop, move erratically or leave one arm still, the fault is more likely to sit beyond the wiping edge.
Start with the blade and windscreen because they are the simplest parts to check. If cleaning, correct fitment and sound blades do not solve the problem, stop treating it as a blade fault. The wiper arm, linkage, motor, switch, fuse, wiring or washer system may need professional attention.
If you cannot keep a clear view of the road, pull over somewhere safe. Do not wait for heavier rain to confirm that the wipers have failed.
Diagnose the symptom first
| What the wipers do | Likely area to check first | Safe first step | When to replace or book a repair |
|---|---|---|---|
| Leave narrow streaks | Dirty or worn rubber; dirty glass | Clean the windscreen and blade edge | Replace the blade if streaks remain or the rubber is split, nicked or hardened |
| Spread a broad smear or haze | Oil, wax, road film or contaminated rubber | Clean the glass thoroughly, then clean the blade edge | Replace the blade if smearing returns on clean, wet glass |
| Skip, chatter or judder | Dry or contaminated glass; worn, twisted or incorrectly fitted blade | Wet the glass, clean both surfaces and check the blade is fitted correctly | Replace a worn or misshapen blade; see a technician if a sound blade still skips |
| Squeak | Dry glass, contamination or a hardened wiping edge | Test only on a wet, clean windscreen | Replace if noise persists; have the arm checked if a new correct blade still squeaks |
| Miss part of the windscreen | Incorrect blade, damaged blade structure or arm-pressure problem | Confirm the blade matches the vehicle and sits correctly | Replace an incorrect or damaged blade; have the arm inspected if contact remains uneven |
| Lift at road speed | Incorrect or insecure blade, damaged blade or arm fault | Check that the connector is locked and the blade is the correct fit | Replace or refit the blade; book an inspection if lifting continues |
| Move slowly, erratically or not at all | Obstruction, arm, pivot, linkage, motor, switch, fuse or wiring fault | Switch the wipers off and check only for obvious external obstructions | A technician should diagnose the mechanical or electrical system |
| Move but do not spray washer fluid | Empty reservoir, dirty nozzle, hose, pump or electrical fault | Top up with suitable washer fluid and wipe visible dirt from the nozzles | Book a repair if there is still no spray, the pump is silent or fluid leaks |
How to fix windscreen wipers safely: five checks
Park on level ground, switch the vehicle off and apply the park brake before touching the blades. Check the owner's manual if the wipers need to be placed in a service position; forcing an arm up when it is not designed to lift can damage the arm or bonnet.
Before cleaning, look for torn rubber, a loose blade or material caught around the arm. Replace a visibly damaged blade, and stop if an arm is loose or obstructed.
1. Clean the windscreen
Road film, car-wash wax, tree sap, insects and grime can make a good blade look faulty. Clean the whole swept area with an automotive glass cleaner and a clean microfibre cloth. If there is a persistent film, repeat the clean with a fresh cloth rather than spreading the residue around.
Check the glass by looking across it in good light. A greasy arc that follows the blade path is a clue that contamination, rather than torn rubber, may be causing the smear.
2. Clean the blade edge
Lift the arm only as described in the vehicle handbook and keep control of it. The spring-loaded metal arm can snap back and damage the windscreen, so place a folded towel on the glass as a precaution.
Wipe the rubber edge with a clean cloth dampened with water or a small amount of mild car-wash solution, then wipe it again with clean water. Remove loose grit gently. Do not use petrol, strong solvents, abrasive pads or lubricant on the wiping edge.
Cleaning can remove contamination. It cannot repair rubber that has split, cracked, hardened or lost its shape.
3. Inspect the blade, connector and fit
Look along the full rubber edge and the blade structure. Replace the blade if you find:
- splits, cracks, nicks or missing pieces in the rubber
- a hardened edge that no longer flexes
- a permanently bent, twisted or wavy blade
- corrosion, damage or loose parts in a conventional frame
- a connector that will not lock securely
- the wrong length or connector for the vehicle.
If the blades were fitted recently, check that any transport protector has been removed and that each connector is fully closed. Driver and passenger blades are often different lengths, so do not assume they can be swapped from side to side.
Some blade frames accept a rubber refill; others use a bonded blade-and-rubber assembly. Fit only the replacement type, length and connector specified for the vehicle and existing blade design.
Use the vehicle handbook, the supplied fitting instructions or WiperPro's installation page for the correct removal and fitting method. If the connector does not release as described, do not force or twist it. Never let a bare wiper arm rest against the glass.
4. Test on wet glass
Lower the arms gently, wet the windscreen with washer fluid and test the wipers at their normal settings while the vehicle is stationary. Do not run them across dry glass. Dry wiping increases friction and can produce noise or skipping that is not present in rain.
Watch both blades through a complete cycle:
- Does the rubber flip direction smoothly at each end of the stroke?
- Is the symptom on one blade or both?
- Does the problem occur in the same place on every pass?
- Do the arms move together at a steady speed?
- Do they return to their normal parked position?
These details separate a blade or glass problem from a system fault.
5. Decide: replace the blade or stop and book a repair
Replace the blade when the rubber or blade structure is worn, damaged, misshapen, insecure or incorrect for the vehicle. If the blade looks sound but cleaning fixes the problem, replacement is not yet necessary.
For a split, hardened or misshapen blade, the practical wiper repair is replacement.
Book a qualified repair when the problem involves arm pressure or alignment, loose or damaged pivots, clashing arms, a failed linkage, abnormal speed, incorrect parking, the motor, switch, fuse or wiring. Those faults sit beyond the blade and need mechanical or electrical diagnosis.
What each wiping pattern usually means
Streaking: narrow lines left after each pass
One or several narrow lines usually mean that grit is trapped under the wiping edge or a small section of rubber is damaged. Clean the glass and rubber, then test again on wet glass. If the line appears in the same place after cleaning, replace that blade.
Several fine streaks across most of the wiped area often indicate an aged or hardened edge. Replace the blade if cleaning does not clear them.
Smearing: a broad film or cloudy arc
Smearing is different from streaking. Instead of leaving a narrow line, the blade spreads water or residue over a wider area. Start by removing oil, wax and road film from the windscreen. Clean the blade edge separately so residue from one surface is not transferred back to the other.
If a clean blade smears a clean, wet windscreen, the rubber may no longer flex and change direction correctly. Replace it. If new blades smear in exactly the same area, the glass may still be contaminated or the arm may not be holding the blade squarely; have the fitment and arm checked before buying another set.
Skipping or chattering: the blade jumps across the glass
A blade can chatter when the glass is dry, the windscreen or rubber is contaminated, the blade is installed incorrectly, or the wiping edge has become stiff or distorted.
Clean and wet the glass first. Confirm the connector is locked, the blade is not twisted and the correct blade is fitted on each side. Replace a worn or distorted blade. If the blade is new, correctly fitted and still skips on clean, wet glass, the arm angle, spring pressure or pivot may be at fault.
Do not bend the wiper arm or alter its spring tension as a trial-and-error fix. Too much or too little pressure can worsen wiping, damage the blade or cause the arm to sit incorrectly. Ask a technician to measure and correct an arm fault.
Squeaking: noise without obvious skipping
Squeaking often comes from dry glass, contamination or a hardened rubber edge. Wet the screen, clean both surfaces and test again. Persistent noise from an old blade is a replacement trigger.
If a new, vehicle-correct blade squeaks after the windscreen has been cleaned, check the installation once. If it is secure and untwisted, the arm or glass condition needs assessment. Do not apply oil or silicone spray to silence the wiping edge; it can leave a film in the driver's field of view.
Missed patches or uneven wiping
A missed area can come from the wrong blade length, an incorrectly fitted adaptor, a bent blade structure or uneven arm pressure. Compare the fitted blade with the vehicle application and installation instructions. Replace it if it is incorrect or physically damaged.
When a correct, undamaged blade consistently misses the centre or one end of its sweep, the arm may be bent, corroded or losing spring pressure. That is an arm fault, not a reason to keep replacing blades.
When the fault is not the blade
The blade is the rubber-and-frame assembly that contacts the glass. The arm holds that assembly against the windscreen. Under the panel at the base of the windscreen, the linkage transfers movement from the motor to the arms. The fuse, switch and wiring supply and control the system.
Signs that the fault sits beyond the blade include:
- neither arm moves and the motor is silent, which may point to the switch, fuse, wiring or motor
- the motor can be heard but neither arm moves, which may point to a failed linkage
- only one arm moves, which may point to a pivot or linkage fault
- the arms fall out of sequence
- the arms move slowly, stop part-way or change speed unexpectedly
- the arms clash, travel beyond their normal sweep or park in the wrong place
- there is grinding, knocking or movement at the base of an arm
- a replacement fuse fails again
- sound blades do not maintain even contact with the glass.
Switch the system off if an arm is loose, out of sequence or obstructed. Continuing to operate it may add damage. Do not remove trim, dismantle the linkage, bypass or repeatedly replace a fuse, probe wiring or open the motor for a roadside diagnosis. A qualified automotive technician or auto electrician can isolate the arm, pivot, linkage, motor, switch, fuse or wiring fault.
Washer fluid problems
Wipers cannot clean road grime effectively without washer fluid. If the blades move but no fluid reaches the windscreen:
- Check the reservoir and top it up with a washer fluid suitable for the vehicle and local conditions.
- Look for washer fluid under the vehicle or in the engine bay without removing covers or hoses.
- Wipe visible dirt from the outside of the washer nozzles.
- Try the washers briefly and listen for the pump.
Do not keep running the pump if the reservoir is empty. If the tank is full but the pump is silent, fluid leaks, spray remains weak or the nozzles repeatedly block, have the washer system inspected. The cause may be a hose, pump, electrical supply or internal blockage rather than the wiper blades.
How to avoid repeat wiper problems
- Keep the windscreen and blade edges clean, particularly after dusty driving, coastal spray, insects or tree sap.
- Use washer fluid rather than operating the blades on dry glass.
- Clear leaves and other loose debris from around the wiper arms before switching them on.
- Do not use the wipers to move heavy debris or free blades stuck to the glass.
- Check that replacement blades match the vehicle and lock securely into the arm.
- Inspect front and rear blades before long trips and before periods of wet weather.
For routine blade care, see the WiperPro guide. If worn, damaged or incorrect blades are the confirmed cause, compare wiper blade options for Australian conditions and use WiperPro's make-and-model selector to find a replacement.
Frequently asked questions
Can damaged wiper rubber be repaired?
No. Cleaning can remove dirt and residue, but split, cracked, hardened or misshapen rubber needs replacement. Do not trim, sand, soften or glue the wiping edge.
Why do new wiper blades still streak?
The windscreen may still have oil, wax or road film on it. The blade may also be the wrong size, fitted to the wrong side, twisted in the connector, not fully locked, or still covered by a transport protector. Clean the glass, check the installation and test on wet glass. If the blade is correct and the fault remains, have the wiper arm checked.
Should I adjust wiper arm tension myself?
No trial-and-error adjustment is recommended. An arm with the wrong angle or spring pressure can cause missed areas, chatter or accelerated blade wear. A technician can check the arm, pivot and spring without risking damage to the windscreen or wiper system.
Can I drive with failed windscreen wipers?
Do not drive in rain or any condition where the windscreen cannot be kept clear. If the fault develops while driving, slow down, pull over safely and arrange repair or assistance.