My rear window defroster works poorly, it turns on but it takes over 20 minutes to defrost the rear window. When I dropped it off at the dealer to fix another problem ( the key in my ignition cylinder rotated 360 degrees half the time I tried to start it.) the wise mechanic told me there was no code so there was nothing wrong. I would hook up a volt meter or ohm out the filiament but I do not know what the readings should be.
Help.

 

Did you buy the car used?

If so the windows might have been tinted at one time.
When the tint is taken off even a knick in one of the elements will cause it to not work.

I have used a test light before to test for power on the elements.

 

The windows were not tinted when I bought it but I have had them tinted, the defroster didn't work before I had them tinted. As far as I can tell the filiments are not damaged, they all eventually heat up with no breaks in the lines so I am thinking they are not getting enough juice to heat up my window.

 

They aren't made to take off an inch of ice, just frost. And they don't work immediately. (The rear window defroster also defrosts the side view mirrors). Try starting your car and running the heat for about 5 minutes to defrost all the windows before you go somewhere. That should help alot. Another thing that can help the rear windows is mixing generic anti-freeze with some window cleaner (what you use for your front windshield) and use a windex spray bottle. Just spray the window down well after its been heating, and that should help.

 

My side view defrosters do not really work either, I can't even tell if they work at all. If there is any dew on my windows, not frozen ice but just the regualar moisture that shows up really early in the morning it will still take 15 minutes to defrost to the point where I can see out the back. If I do have ice on the window I will get to work before I can see out the back so I know that this defroster is not working as it should.