MOT defect file
Wiper or washer not working properly
Last updated
Quick answer
The wipers or washers cannot clear the screen adequately. Usually blades, a blocked jet or a failed pump.
- Typical cost
- £15–£120
- DIY viability
- Straightforward
What you might notice
- Streaks, smears or an untouched band of glass left behind after each pass
- Juddering or chattering across the screen rather than a smooth sweep
- Washers that dribble instead of reaching the glass, or jets aimed over the roof
- A wiper parking in the wrong place, moving out of step with its partner, or stalling when the screen is wet and heavy
What causes it
- Perished or split blade rubber — blades are a consumable and last roughly six to twelve months
- Blocked washer jets, from limescale where plain water has been used or from wax after a valet
- A failed washer pump, a split feed pipe, or a cracked reservoir that empties itself
- A worn wiper linkage or a slipping spline at the arm, and on older cars a motor with worn brushes
Advisory or failure?
The test asks whether the wipers and washers together give the driver an adequate view of the road, and both are checked. A wiper that does not operate, or a blade so deteriorated that it no longer clears the screen properly, is a major defect; a blade beginning to deteriorate but still clearing adequately is a minor defect. Washers are graded the same way — no fluid delivered at all, or too little to clean the screen, is a major defect, while a jet that works but weakly is a minor. It is worth being blunt about the most avoidable failure on the entire test: an empty washer bottle is a major defect and will fail the car, so top it up before you go.
Can you fix it yourself?
Straightforward
Blades clip on and off in a couple of minutes. Buy the right length for each side, since driver and passenger blades are usually different, and lower the arm back gently — the spring will crack the screen if it snaps down onto bare glass. A blocked jet clears with a pin or a puff of compressed air, and the same pin adjusts the aim. If the pump hums but nothing arrives, look for a split pipe under the wing or a hose off at the reservoir before condemning the pump. Use proper screenwash rather than plain water: it keeps the jets from furring up and stops the reservoir freezing, which is what splits it.
What it costs
A pair of blades is £15 to £40 depending on the fitment, and fitting them yourself takes minutes. A washer pump is £10 to £30 in parts, with the labour depending entirely on whether the reservoir has to come out to reach it, which sometimes means removing a wheel arch liner. The top of the band is a wiper motor or a linkage assembly at £60 to £120 fitted. Flat-blade and heated blades on newer cars cost noticeably more than conventional ones.
What happens if you ignore it
This is the cheapest thing on the list to fix and one of the worse ones to leave, because the failure mode is losing your view of the road at the worst possible moment — low winter sun on a smeared screen, or spray off a lorry with nothing in the bottle. A wiper dragged across a dry or gritty screen also scores the glass permanently, and a torn blade lets the metal frame reach the glass and cut a curved scratch right across the driver's view.
This is general guidance, not a diagnosis. The severity DVSA records depends on the specific fault found, so the same item can appear as an advisory on one test and a failure on another. Ask a qualified tester or mechanic to inspect the vehicle.
Has this been recorded on your car?
Check the full MOT history for any UK registration.