Rear window defogger resistors?

I have a digital air conditioner in my car. When I press the button of the demister rear window heaters, there is no change in the screen nor the circuit starts to work. I wonder if my car doesn't have this feature? & nbsp;

If there is any feature, it may be a problem or have a look at insurance & nbsp; berk2309 2012-08-28 01:22:15