Will Non-Functional Windows Fail Your MOT?

The annual MOT test is a crucial assessment for vehicles across the UK, designed to ensure they meet minimum road safety and environmental standards. Many drivers fret over various components, from tyres and brakes to lights and emissions. A common question that often arises, particularly for those with older vehicles or cars that have seen better days, is: "Will my car fail its MOT if the windows don't work?" While it might seem like a minor inconvenience, the answer isn't a simple yes or no; it largely depends on which window is affected and why.

The MOT and Window Functionality: What's the Rule?

When it comes to the MOT test, the primary concern regarding windows revolves around driver visibility and the ability to perform certain actions crucial for road safety. The specific regulations are quite precise, and understanding them can save you a lot of worry – and potentially a retest fee.

The Critical Driver's Side Front Window

This is arguably the most important window on your vehicle for the MOT test. The rules state that the driver's side front window must be able to be opened. Why? There are a couple of key reasons:

• Hand Signals: Although less common with modern vehicles, the ability to give hand signals is still a requirement in the Highway Code. If your indicators fail, or in certain situations like sun glare, you might need to use hand signals. If your window is jammed shut, this becomes impossible.
• Communication & Convenience: Think about common scenarios like paying at a toll booth, using a drive-through, or communicating with emergency services. While not strictly a safety issue in all cases, the inability to open this window can hinder basic driving functions.

Therefore, if the driver's side front window cannot be opened, whether due to a faulty motor, a broken switch, or being jammed, it will result in an MOT failure. It's a clear-cut rule because it directly impacts the driver's ability to operate the vehicle safely and communicate effectively.

Other Windows: Passenger and Rear

Unlike the driver's side front window, the functionality of other windows – such as the front passenger window, rear passenger windows, or the rear windscreen – is generally not an MOT testable item. This means that if these windows are stuck open, stuck closed, or simply don't operate, it will typically not lead to an MOT failure.

However, while not a direct fail, there are caveats:

• Safety Implications: A window that is stuck open could allow excessive wind noise, ingress of rain, or even pose a security risk. A window that is stuck closed could prevent an emergency exit for passengers in an accident. While these aren't MOT fails, they are practical considerations for vehicle owners.
• Visibility (Rear Windscreen): While the rear windscreen's opening mechanism isn't tested, its overall condition for visibility is. Any significant cracks, damage, or obscuration that impairs the driver's view through the rear-view mirror could lead to a failure.

Beyond Functionality: Other Window-Related MOT Checks

It's important to remember that the MOT test covers more than just whether your windows go up and down. Other aspects of your car's glazing are rigorously checked:

Window Tinting

Tinted windows are a common modification, but they can be a significant cause of MOT failure if not compliant. The rules for tinting are strict:

• Front Windscreen: The front windscreen must allow at least 75% of light through.
• Front Side Windows (Driver and Front Passenger): These must allow at least 70% of light through.

If the tinting on these windows is too dark, it will lead to an MOT failure as it impairs the driver's visibility and the ability for others to see into the vehicle, which can be a safety concern. Rear windows and the rear windscreen can be tinted to any level, as long as the vehicle has two working side mirrors.

Condition of Glass

Any significant damage to the windscreen or windows can also lead to a failure:

• Windscreen Damage: Chips or cracks in the "swept area" (the area covered by the wipers) that are larger than 10mm in the driver's direct line of sight (a 290mm wide band centred on the steering wheel) will fail. Outside this area, chips larger than 40mm will fail.
• Other Windows: While minor scratches or chips on other windows may not fail, any damage that significantly impairs the driver's view or poses a safety risk (e.g., shattered glass held by tint film) could be cause for concern.

Associated Components: Wipers and Washers

While not windows themselves, the window wipers and washers are intimately connected to your vehicle's glazing and driver visibility, and they are definitely MOT testable items. A common reason for MOT failure is often related to these components:

• Windscreen Wipers: All wipers must work effectively to clear the windscreen. Blades must not be split, perished, or detached, as this would impair the driver's view. If your wipers are streaky, noisy, or leave uncleared patches, they could fail.
• Windscreen Washers: The washer system must be operational and direct fluid onto the windscreen to effectively clean it. If the jets are blocked, the pump is faulty, or the fluid reservoir is empty, it will result in an MOT failure.

Ensuring these systems are in perfect working order is just as critical as checking your actual windows.

Common Reasons for Window Failure

If your driver's side window isn't working, it's usually due to one of several common issues:

• Faulty Window Motor: Over time, the electric motor that powers the window up and down can wear out or burn out.
• Broken Window Regulator: This is the mechanism, often cable-driven, that guides the window glass. Cables can snap, or plastic components can break.
• Electrical Issues: This could be a blown fuse, a faulty switch (either the master switch on the driver's door or individual window switches), or damaged wiring.
• Mechanical Obstruction: Sometimes, debris can get lodged in the window mechanism, preventing it from moving freely.

Pre-MOT Checks for Your Windows and Visibility

Before your MOT test, it's wise to perform a few simple checks related to your car's windows and visibility:

1. Driver's Window Test: Fully open and close the driver's side front window several times. Ensure it moves smoothly, without sticking or making unusual noises.
2. Other Windows: While not a fail, check these for your own convenience and safety.
3. Windscreen Condition: Inspect your windscreen for any chips or cracks, particularly in the swept area and the driver's direct line of sight.
4. Tint Check: If you have tinted windows, ensure they comply with the light transmission regulations for the front windscreen and front side windows.
5. Wipers: Turn on your wipers and check that they clear the screen effectively, without streaking or juddering.
6. Washers: Activate the washers and ensure fluid sprays onto the windscreen and the wipers then clear it. Top up your washer fluid if necessary.

Taking these few minutes to check these items can save you the inconvenience and cost of an MOT retest.

Table: MOT Relevance of Window Components

Frequently Asked Questions (FAQs)

Q1: Can I fix a broken window myself before the MOT?

A1: If you have the mechanical aptitude and the right tools, replacing a window motor or regulator can be a DIY job. However, electrical issues can be trickier. If in doubt, it's always best to consult a professional mechanic. For windscreen chips, many repair kits are available, but professional repair is often recommended for larger or more complex damage.

Q2: What if my driver's window is stuck open? Will it fail?

A2: Yes, if your driver's side front window is stuck open, it will fail the MOT. The requirement is that it must be able to be opened *and* closed. Being stuck open prevents the ability to give hand signals effectively (as the window needs to be rolled down for this) and also poses security and weather ingress issues.

Q3: Does a broken rear window heater affect the MOT?

A3: No, a non-functional rear window heater (demister) is not an MOT testable item and will not cause a failure. While it's a useful feature for visibility in cold or damp conditions, its functionality is not part of the mandatory safety checks.

Q4: What if I have a temporary repair on my window, like tape?

A4: Any temporary repair that is not secure or could become dislodged, or that impairs the safe operation of the vehicle (e.g., tape obstructing the window's movement or a large crack taped over), is likely to result in an MOT failure. Repairs must be permanent and robust.

Q5: My electric windows sometimes work, sometimes don't. Is this a fail?

A5: If the driver's side front window is intermittent, and it fails to operate during the MOT test, it will be marked as a failure. For the purposes of the test, if it doesn't work when checked, it doesn't work. It's best to get it reliably fixed before the test.

Conclusion

To summarise, while a non-functional passenger or rear window typically won't lead to an MOT failure, a broken or stuck driver's side front window absolutely will. This is due to its critical role in enabling hand signals and basic communication. Furthermore, remember that the condition of all your vehicle's glass, particularly the windscreen, along with the effectiveness of your wipers and washer jets, are all strictly checked during the MOT. A little proactive maintenance and a thorough pre-MOT check can ensure your vehicle passes with flying colours, keeping you safe and compliant on the UK roads.

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