Rear defroster doesnt work already reset breaker and check fuses but one fuse in manual not on panel

I think this is a grid type(wires) rear defroster as opposed to a fan style.then when you push the button to turn on the rear defroster you should hear a click this tells you the system is working from the fuse to the rear window.what you have to do is check the rear window grid(wires) with a test light and you will probably find some of the grids not working which indicates a break in the grid line and needs repair.you start with a test light at one end and you should see it light up brightly at one end of the grid and as you move along the grid wire to the other side of the window you should see the light gradually get dimmer,when you hit a spot were the light stops working you just have to norrow down the area of the break and mark it with a marker below the grid,when you have done the complete window you will know the areas that need repair.you can buy a defroster grid repair kit and repair it.follow the directions.before checking the grid wires check the area where the car wires connect to the window at both sides of the window.sometimes there is a problem in this area.