used car with bad rear defroster

I purchased a car very recently with a defective rear window defroster. Is the dealer obligated to fix it? I understand how somethings can't be foreseen and are just too bad for the purchaser but in this case the dealer probably should have known that the defroster was bad. (I live in Iowa and it gets cold this time of year.) I was not informed of the defective defroster at the time of purchase. Any advice will be appreciated.

When you purchased the car, you signed a purchase agreement with the dealer. And most states require car dealers to post in the windows of vehicles they sell terms under which the vehicle is sold. If the vehicle is sold "as is", you are purchasing the vehicle in the condition the vehicle is in at the time of purchase, including any defects. If the vehicle is sold with a warranty, you should have received a list of everything covered by the warranty. All of this should have been spelled out to you at the time of purchase. You could go back to the dealer and let them know about the bad defroster and see if they might honor a "good faith warranty", they want you as a customer again so they will fix the car. Have you checked the fuse box? It could be something a simple as replacing a 50 cent fuse.