How a defroster works

Automotive defroster is a component that is commonly used. Front heaters usually use airflow, while rear heaters are electric.

Whether it's a cold winter day or it's humid outside and the front or rear windows are fogged up, having a reliable defroster is vital to maintaining visibility. A fully functional car defroster is a valuable component for your car, especially on those cold winter days when you have frost or ice on your windshield. While older models only have defrosters on the front windshield, many newer models also have them on the rear window to improve visibility for drivers.

The actual components used to activate the front and rear defrosters vary depending on the year, make and model of your vehicle. In general, the information below will give you a general idea of ​​how these systems work.

What is the job of a window defroster?

There are two different types of defrosters: front defrosters and rear defrosters. The front windshield defroster is designed to blow a large amount of air around the windshield to disperse condensation that has accumulated on the inside of the windshield. In cool weather, water droplets may form on the windows of the car. Condensation on the inside of the windshield occurs because the air outside is colder than the temperature inside the car. When the temperature gets even lower, the condensation turns into frost or ice, which must be scraped off by hand or thawed with a de-icer.

How do front and rear window defrosters work?

Simply put, the front heater works by circulating air, while the rear heater is charged by electricity. The front defroster has air vents on the dashboard facing the windshield and front windows. The fan and fan motor that controls the heating and air conditioning will also circulate air through these vents to defrost the windows.

The operation of the front heater is unique to your vehicle. In general, to activate the front defroster all you have to do is make sure the vents are open, turn on the fan and turn on the defrost setting and set the desired temperature. In most cases, warmer air blowing into the window will speed this up, but the first time the engine is started of the day, it will take time for the heat to build up.

The rear heater on most vehicles is electric. The rear glass will have thin lines running through the window. These lines are electrical fibers embedded in glass that heat up when activated. This defroster has its own button that you access when you want to defrost the rear window. You will notice that condensation or ice will first dissipate along the lines until the entire window is clear.

How defrosters are activated

Front heaters work best when the air blowing against the window is warm. However, it takes time for heat to build up in the engine and activate the heater core. When the coolant reaches a certain temperature, it opens the thermostat. Hot water will flow through the core of the heater while the fan blows warm air through the defroster vents to warm the windows. Condensation or ice will begin to dissipate when the window reaches the desired temperature. If the heater is not working, the front heater will have difficulty working.

The rear window heater is electrically driven. The lines on the rear window are electric. They heat up when the rear window defroster is turned on and immediately begin to remove condensation. The advantage of an electric defroster is that it starts working as soon as you turn on the car and press the rear defroster button. Many newer models are fitted with electric heaters around the edges of the front windshield to improve the defrost system and remove condensation more quickly.

The heated exterior mirrors also use electric heaters to remove condensation so you can see around the vehicle. The difference is that you don't see any visible lines, as is the case with the rear window defroster. Please note that these heaters provide a small amount of heat and will not burn you if you touch a window while they are activated.

Common Deicer Problems

You often won't notice a defroster problem until you need it and it stops working. This can happen for various reasons:

• Buttons or knobs that are stuck or stop working may need to be replaced or repaired.
• Blown Fuse - When the circuit is overloaded, the fuse that connects to the defroster may blow, the fuse can be checked and replaced by a professional.
• Lack of terminal edges on the window - this may be due to the fact that the tinted glass has begun to crack or the tint has peeled off.
• Lack of Antifreeze - When the antifreeze level is too low, the vehicle may not heat up properly or allow the defroster to work.
• Frayed Wires - Disconnected or frayed wires are interfering with the operation of the defroster.
• Clogged vent - When the vent is clogged with dust and debris, air cannot pass through to heat the windshield.

If the front or rear window defroster is not working, it is recommended that you have a professional mobile mechanic come to your place and complete the inspection of the vehicle's inoperative defroster. This will allow them to pinpoint exactly what is broken or not working so that the correct repairs can be made quickly.