Rear Windshield Defogger

Topic for today is rear windshield defogger which can be easily recognized in the rear windshield of a car as a pattern of multiple thin lines. As the name suggests this system works to remove the fog from the rear windshield of your vehicle when the outside atmosphere is very cold. I will tell you why this system is used and how it is used..So lets, start with why it is used...

Rear Windshield Defogger Button

Why Rear Windshield Defogger :

How do you feel if someone closes your eyes and ask you to walk?? Same feeling comes when a driver has to reverse a car with fog blocking the view. To prevent this from happening the cars are coming equipped with defogger in rear windshield, So that in case there's  fog on the windshield you can remove it just by turning on the defogger. 

Although there's a valid point that fog on the windows and front windshield gets removed just by turning on the Air Conditioner. This process is good but for rear windshield the thing either work too slow or in some cases doesn't work.  For this reason a rear defogger is a must and it works quickly.

Rear Windshield Defogger in Toyota Innova

How does it works:

The mechanism used inside this system is just similar to the mechanism used in Heated Seats. A very basic mechanism in which there is a circuit with few wires and a resistance. The logic behind is that when the current is passed through the circuit the resistance opposes the flow of current through it and thus resistance generates heat. This heat is generated in the resistance which is present on the windshield in the form of wired pattern. As son as heat comes up the fog present near the pattern gets evaporated and we are left with a clear windshield for our ultimate driving experience.

Grid lines present in the rear defogger

Pros:

• Quick
• Very much needed in winters
• Easy mechanism
• Current flowing is very low so no chances of shock in case of touching. 

Cons:

• The wired pattern is very thin and can easily be chipped off if not taken care of.
• Since it is electrical system problems can occur without notice.