Q: I just noticed my rear window defroster has a big gap in the middle that doesn’t defrost. It’s about 2 inches high. I was told the window needs to be replaced to fix this, and it’s really ...

Defrosters clear condensation from windows and melt frost, ice and snow. They work differently depending on whether they are for the windshield or the rear window.

Ray: There are several reasons why the rear window won't break. First of all, the defroster's wires, which are embedded in the window, do not produce an enormous amount of heat.