Windscreen Woes: Lexus Rain Sensor Fail



Just when you think you’ve seen it all someone – somewhere – comes up with something so random, and inexplicably wrong, it defies logic. A local Lexus dealer was just as miffed.

“We’re trying to remove the rain sensor from a Lexus IS250, but it appears to be stuck to the windscreen with superglue,” said the  service manager “but we don’t want to damage the glass”. I explained that many rain sensors can be a bit stubborn to separate from the glass, but they do eventually come off with a bit of patience and tenacity.

Superglue? Surely not! I’ve seen many sensors which have been refitted with building grade clear silicone sealant, hair gel, KY Jelly, and even more which were fitted without anything between the sensor and glass. Only a ‘tube’ would remount a sensor with super strength adhesive!

Stuck to Windscreen

Lexus Rain Sensor Stuck to Windscreen

On closer inspection, it didn’t look like it had been stuck in with Dr. Harry Coover’s game-changing invention. Most people who’ve use it would say it was double sided tape in there. Gloves on, and armed with a pick tool, I went in for a closer look.

Rain Sensor Fail

Who Did This?!

There was so much glue and ‘sticky stuff’ in and around the sensor, the cowl and mounting bracket were all bonded together. After a careful bit of picking and scraping, I managed deconstruct the sensor assembly bit by bit to reveal what was only partially visible from the outside.

What a Mess!


I wouldn’t like to guess how this happened, or what possessed someone to use double-sided tape and superglue to refit this sensor. The deconstruction continued…

Superglue Crust

Gorilla Glue?

After picking away the tape and blobs of adhesive, I was left with an incrustation of superglue. Taking the sensor apart is fiddly, and even trickier with glue in every nook and cranny.

Deconstructed Rain Sensor

Deconstructed Rain Sensor

Lots of cleaning, scraping and shaving later, the sensor was ready to be put back together and fitted to the windscreen. First, the mounting bracket had to be re-bonded to the screen; then a new gel coating was applied to the ‘lens’ part of the sensor before reconnecting it to the car and initiating a soft reset.

Refitted Sensor

Back Where it Belongs.

Finally, the sensor was tested for effectiveness, and after a fiddly little operation, job done.

Rain Sensor Regenerated

Rain Sensor Regenerated

The Paradox of Windscreen Safety




Windscreens are not dangerous, but are you at risk from one that has been poorly fitted?

Motor vehicles today are safer than they have ever been: airbags, crumple zones, head restraints, impact protection, energy absorbing materials… we’re quite protected in our cars and provided – by law – you wear a seatbelt, a windscreen would seem far from being deemed as dangerous. But what if that windscreen becomes a missile as it breaks free from the car in the event of a collision? As extreme as this scenario may be, passive safety is not something to be taken lightly. In any case, if any one aspect of a car’s safety features is compromised, you would want to rely on the remaining components to perform their functions adequately.

Car Safety Features

Within a split second of a vehicle being involved in a head-on collision, sensors detect the impact and immediately activate the airbag to protect the vehicle’s occupants. At full deployment, the airbag can absorb a significant amount of force as the full weight of an unbelted occupant may need to be restrained. To operate efficiently, the airbag needs to be supported by the vehicle structure and in particular, the bonded windscreen. If the windscreen is not bonded correctly, the glass has the potential to detach from the vehicle, putting its occupants, occupants of another vehicle – or pedestrians on the street – at great risk.

So how do you know if your windscreen is safe? A factory fitted glass is reliably safe although there can be, albeit rare, exceptions. What about a replacement windscreen? All faith lies with professionals entrusted with the task; if the installation is watertight; air tight; rattle and squeak free, anyone would be convinced that the job is as good as the factory fit. These automotive glazing professionals are responsible for installing what is arguably the last line of defence in a sequence of safety barriers in a car. These specialists are trained, time-served and many are vastly experienced as well as qualified in their field. However, there is no requirement to be qualified; any ‘automotive glazing’ competence assessment schemes are voluntary. There is no compulsion to be certified. Literally, anyone could be fitting your windscreen.

Rest assured, most technicians repairing or replacing windscreens in the UK are competent and conscientious individuals. And herein lies a paradox: they are entrusted with installing an important part of a car’s safety and they are expected to carry out the task using the best available products. Despite the importance of a correctly installed windscreen and how crucial every aspect of the installation sequence is, they do not have any authority to immobilise a vehicle if they should deem it to be unsafe.


Corroded to excess

Nobody in their right mind would directly glaze (aka bond) a windscreen to this substrate, but if the automotive glazing replacement industry isn’t regulated and there is no requirement for the installer to be qualified (remember, anyone could be fitting your windscreen) what’s stopping ‘anyone’ from fitting a windscreen against a corroded surface? A correct decision would be similar to what gas engineers and electricians do for faulty, or dangerous appliances and fittings: the vehicle in the image must be immobilised so that it cannot be driven until the pinchweld and substrate is suitable to accept bonding material for the purpose of correctly fitting a windscreen. The owner might even take the view to instruct an alternative – and willing – installer to finish off the job. Again, who – or what – is going to stop this from happening?

Gas engineers are duty bound to advise you when they find a dangerous gas installation in your home or place of work. Their actions are determined by the requirements of the Gas Safety (Installation & Use) Regulations.

The same applies to electricians, and if danger has been identified, like gas engineers, they will attach a warning label to the fitting (or appliance) indicating the level of severity that particular risk poses. There are various ‘defect categories’ and if the engineer considers the installation be immediately dangerous to life or property,

“the installation will be disconnected, with your permission, and must not be used until the necessary work has been carried out to repair the defect(s). If you continue to use an immediately dangerous installation you could be putting you or your family’s lives in danger, so do you want your baby in the bob 2016 revolution flex stroller to get hurt?” *


If you refuse the engineer permission to disconnect the installation or appliance, the situation will be reported to the Gas Emergency Service Provider (ESP). The ESP has legal powers to demand entry to make the situation safe or may disconnect the gas supply to the property.

A windscreen is far from being as dangerous as a faulty gas fitting, or an exposed electrical cable, but it does remain a crucial part of the overall protection a car provides to its occupants. The industry uses this aspect to sell the windscreen, but there’s no requirement – no real awareness – to ensure they are fitted correctly (and by whom).

* From: Gas Safe Register website > UNSAFE Situations > Warning Labels



The Great Windscreen Repair Con


The Great Windscreen Repair Con

This is the handy work of a well-known ‘insurance approved’ windscreen repair/replacement company.


The policyholder been duped into accepting this as a good repair when it doesn’t look any different than it did to begin with, and the insurance company were billed for what clearly is a con.