Why Are My Defrosters Not Working?

Everyone has experienced morning frost or ice covering their windshield. When there's a blanket of ice on your windshield, you have no choice but to count on your vehicle's defrosters. Your defrosters are very important to have, especially this time of year. So, if your car defroster stops working, it's only reasonable to wonder why. Read on to learn more about your vehicle's windshield defroster and why it may be malfunctioning.

To start off, most vehicles today have both front and rear defrosters. And they both work independently. Front defrosters come from vents controlled by the car's heating and cooling system, whereas rear defrosters are wired electrically. 

A broken defroster can make your commutes hellish; these are some reasons why your front or rear defroster may stop working:

Stuck Controls (Front)

Broken buttons are a typical case of a defective front defroster. If the dial or buttons are jammed, it won't engage the defrosters - simple as that.

Blockages (Front)

If the blower motor is running and there is no air coming out of your vents at all, something within the HVAC system may be clogged. Typically, jams occur with the fresh air intake.

Low Coolant Levels (Front)

Since your vehicle's HVAC system relies on coolant to power your heat, A/C, and defrosters, running low on this solution can wreak havoc on your car. You can simply test it by blasting your A/C; if you get cool air, it means you still have coolant.

Damaged Wires (Rear)

Wires go frail and break over time. Additionally, a vehicle accident can cause damage to them. Our technicians can inspect the wires to get down to the bottom of the problem.

Burnt Wires (Rear)

Wires can break, but very old ones can even burn out. This is a rare case unless you have a much older car.

Bad Fuse (Rear)

Bad fuses are pretty popular for rear defroster problems; thankfully, this problem is relatively easy to narrow down. Typically, the fuse is one of the first things your tech will check. 


If you need help diagnosing and repairing your vehicle's defrosters, please bring your car to Autoworks of Issaquah. Don't delay this repair, as it can slow down your winter morning routine and become a massive headache altogether.

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