Rain Sensor Windshield

What is a Rain Sensor Windshield?

A Rain Sensor is a very popular and convenient electronic device used with Windshields in automobiles that uses a optical sensor to detect rain, sleet or snow and controls the speed of the windshield wipers.  This device can reduce or increase the rate at which the wipers operate.  Rain sensors work by projecting infrared light into the windshield glass at a 45-degree angle.  When the glass is dry most of the light gets reflected back into the sensor by the surface of the windshield or windscreen.  When the glass gets wet it impedes the ability for the light to be reflected back to the sensor causing the wipers to activate.  The less light that reflects back the faster your wipers will operate.  The sensor is very delicate and cannot be scratched during a replacement.

The rain sensor is usually located on the windshield and looks either like a box that surrounds the rear view mirror or is circular and close to the rear view mirror.  If you are not sure if you have one look closely from the outside of your windshield at the rear view mirror and you can usually see an area that is circular and clear without any shade or tint from the Frit covering the sensor area.  Try to see if you can see a sensor that will let you know you have a rain sensor.  Another way to tell is if you wipers come on automatically when it rains.

The driver can take control of the system at any time.  Remember you should always turn off your wipers before entering a car wash.  You can select from five different sensitivity settings typically on any vehicle.  These settings determine the speed and frequency of the wipers based on the amount of moisture detected.  The higher the sensitivity setting the less moisture is allowed to accumulate on the windshield by rule of thumb.

How Much Do Rain Sensors for Car Windshields Cost?

Rain Sensors will typically make the windshield replacement cost be a little bit higher.  There’s a variety of rain sensors on the market and some vehicles are different then others making the replacements more work due to the sophistication of the device.  Some will attach to the windshield with clear double sided adhesive while others are mounted on a bracket and built into the glass others are part of the rear view mirror assembly and require special tools to remove properly.

An experienced technician should test to make sure the rain sensor is working properly prior to removing the existing windshield.  Rain sensors will not work if any doors or windows are open.  Once the sensor is disconnected the tech should never turn the vehicle back on until the old sensor is reconnected or the new sensor is connected.  If the vehicle is turned on while not being connected it could cause damage to the sensor and require the vehicle be returned to the dealer to be recalibration.

If the rain sensor is not installed properly and if there are any air bubbles or gaps it will cause the sensor to remain on.  It should be at least 60 degrees F out when installing the new sensor otherwise you may experience problems.