Q: When you turn on the defroster/defogger, is the windshield supposed to defog instantly?

asked by on

In the morning when the windshield is fogged up, when you turn on the defroster is it supposed to instantly clear the windsheild or will it take a few minuets to clear?

My car has 12100 miles.
My car has an automatic transmission.

This can actually take a few minutes - and depends on the temperature and level of moisture in the air inside as well as outside the vehicle. Two things happen when you use "Defrost/Defog". The air needs to be heated, and the air needs to be "dry" (low moisture content). Engine heat provides the heated air (through the heater ducts), and the AC system takes moisture out of the air inside the car while cooling it. But then this cool air requires more heat to help defog. So, as you can see - the engine has to heat up, and the AC has to work a few minutes to dry out the air inside the car. Great question!

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. When you turn on the defroster/defogger, is the windshield supposed to defog instantly?

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

Get a quote

What others are asking

Q: Why doesn't my defroster work in my 2003 Pontiac Sunfire

Hello. If the rear defroster is working like you explain then it sounds like the rear window needs to be replaced. As the element in the window begins to short out internally various parts of it will stop working until...

Q: Car took longer to start than usual

Hi there, thanks for writing in. Although your car is nearly brand new, it certainly isn't impossible for it to have a failed battery. If it cranked over slowly as it was starting, it could be an indication that the...

Q: Is it bad to floor the gas pedal on your car?

Occasional severe acceleration is substantially harmless to an otherwise normally functioning engine. The issue of accelerated wear typical arises if the severe use is consistent and continuing over a period of time. Rates of acceleration, high or low, have absolutely...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...