the defroster is actually your a/c. it doesn't run much when it's cold outside but it works with your heater to remove the moisture from inside the car. blowing warm dry air on the windshield. just like it removes the moisture (humidity) from inside the car in the summer. the difference is the temp. you have it on. even if the a/c don't work, the heater will still do the job, just not quite as well.
It is probably the sound of the defroster fan.
The 1953 Lincoln was the first car that had a rear window defroster. It also was the first car to have an optional 4 way power seat.
windshieldwheelwater pumpwindowwindow defroster
If you have the defroster in the on position the ac will do that.
It heats the windshield to melt the ice.
Because it's not a defroster button! It's just the symbol for ventilating the air into the car. It shoudln't be called a defroster since defrosting is meant by heating up the coils that you see at the back of the car. I'm pretty no car has wires in the front!
Defrost the windshields so you can see where you are going. Useful in icy climates.
dry air removes moisture better
You have a leaking heater core. You might smell antifreeze if you turn on the defroster.
If there is an oil leak inside the engine compartment of the vehicle. The defroster could have some of the smell go into the cabin of the car. The engine should be checked for any oil leaks.
· windshield washer pump · water pump · window defroster · windows
If you have the defroster on, the ac comes on automatically.