Q: How Does a Car's Rear Defroster Work?
How does a car's rear defroster work?
Recommended Services
| Defroster is not working Inspection | $94.99 - $114.99 | Get a Quote |
Most vehicles have an electrical grid on the rear window that will warm the glass to clear fogging or frost. The rear defroster grid is applied to the inside of the glass by the manufacturer and actually conducts electrical current when it is turned on. There is typically a timer built in to the circuit that will automatically turn it off in 15 minutes or so, since it tends to get forgotten after the glass has cleared.
Larger vehicles like vans and SUV’s commonly have rear defrost capability built into their rear A/C and heating systems. These function are much like the defroster in the front but using dedicated blower fan which ducts direct airflow onto the rear glass. Should you run into any problems with this system, have a professional mechanic diagnose your defroster to accurately repair your vehicle.
The statements expressed above are only for informational purposes and should be independently verified. Please see our
terms of service
for more details
Get an instant quote for your car
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing
What others are asking
steering wheel noise
The shaking could be your tie rods. There are two sets of tie rods on your vehicle. The two inner tie rods and two outer tie rods. The outer tie rods are easily replaced but require the car to be...
Jeep running rough
An older vehicle like this requires a lot more hands-on tuning and adjustment. Things such as timing, dwell, spark plug, point gap, and carburetor adjustments all should be finely tuned. Getting a vehicle running requires knowledge of those adjustments and...
My rear brake sounds like it's creaking what should I do?
Hello. Creaking is usually due to the brake pad hardware kit being worn. The hardware kit keeps pressure on the brake pads during braking and dampens vibrations. I always recommend replacing the hardware kit when replacing the brake pads since...
Will turn over but won't spark to start, 1987 Chevrolet Cavalier
Hey there, thanks for writing in about your 1987 Chevrolet Cavalier. As you may already know, your car needs air, fuel, and spark to start. You have covered most of that already. If it is not getting spark, start by...
What type of oil do I use in my altima
That's a good question. I did some research and it says 0W20. However, there is a small chance that my information is incorrect. Most vehicles, especially new ones, you can find the oil type on the oil fill cap. It...
high rpm when starting car, then idles very rough. Also lack of power accelerating at times while driving
These codes all point to the operation of the throttle position sensor (https://www.yourmechanic.com/services/throttle-position-sensor-replacement). The throttle position sensor (https://www.yourmechanic.com/services/throttle-position-sensor-replacement) is a sensor used to monitor the throttle position relative to your foot on the gas pedal. The sensor is usually located...
My Volkswagen Golf GTI is idling above 1000 revs and engine stalls
First you want to look for vacuum leaks. Any air that gets into the engine without going through proper channels can cause bad behavior like you describe. Look under the hood for broken or loose vacuum hoses or any large...
changed the fuel pump on 1999 dodge ram 2500 diesel fuel truck. Now, it doesn't send power to fuel pump.
At key on, the fuel pump is normally only powered momentarily to pressurize the system. If you are testing during this brief interval, you have to apply a volt meter at the instant the key is turned on. Otherwise, the...
Replacing just the AC compressor and belt
If the compressor is replaced, the only mandatory component to change is the system drier. If the belt is worn or old, it should be replaced. Replacement of any and all other parts is simply subject to a diagnostic and...
Related articles
Is It Okay to Drive a Vehicle With Windows that Won’t Roll Up or Down?
When When you drive, you need to roll down your window for many different reasons. You might need to: Speak with a peace officer at a traffic stop Order at a drive-thru window Open the window for air flow Open...
How to Safely Break Into Your Own Car
If you locked keys in your car you may need to break into your car to get them out. Use a coat hanger to or slim metal tool to open a locked car door.
How to Reset Automatic Windows
Technology Technology is great most of the time. It used to be that you could replace the battery in your vehicle and not have to worry. However, many modern cars will lose the automatic window function after battery replacement (https://www.yourmechanic.com/article/how-to-change-a-car-battery_2)....
Browse other content
Estimates
Maintenance
Services