The rear window defogger switch is located on the front of your vehicle and turns on the defogger on the rear window. This is a safety feature of modern cars that allows the drivers to be able to see out of the rear window in adverse weather. It turns on the wires mounted on the back window of your vehicle, which helps to melt the snow and ice from the window. In addition, it helps to clear the moisture that builds up causing a foggy window and blocks your view. If you believe your rear window defogger switch is going bad, check for the following symptoms:
1. The window will not clear
Once you push the rear window defogger switch, the defogger should turn on and the window should clear in just a few minutes. If the window does not clear, there could be an issue with the defogger switch. The switch powers and completes the circuit of the electrical grid, so if part of the grid does not work, the switch will not work. Contact a professional mechanic to inspect the electrical system in your vehicle and replace the rear window defogger switch as needed.
2. Button will not light up
When you press the window defogger switch, it should light up indicating it has turned on and will go to work once it has heated up. If the light does not illuminate, this could be a fuse issue, a switch issue, or a combination of issues. Since there are several components that make the rear window defogger work, a mechanic should inspect the vehicle’s systems to properly diagnose the problem.
3. Defogger works sometimes
If you notice the rear window defogger works sometimes but not others, this could be a switch issue. The switch has not gone bad yet, so there is still time to get it repaired before it completely fails. The rear window defogger is important because you need to see out the back while driving. If it is not working correctly, this can be a safety issue so you should have it repaired as soon as possible. This type of intermittent issues can be hard to detect. Consult a qualified technician such as one from YourMechanic to assist with diagnosis.
If your rear window will not clear, the rear window defogger button does not light up, or the defogger is not working all of the time, contact a professional mechanic. YourMechanic makes getting repairs to your rear window defogger switch easy by coming to your home or office to diagnose or fix issues.
You can book a service online 24/7. YourMechanic’s qualified technicians are also available for any questions that may arise. The rear window defogger is important because it helps you see while you are driving, so if it is not working properly it is a safety concern.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Rear Window Defogger Switch and was authored by Spencer Clayton.