I'm having an issue with my rear defroster, it doesn't work. I have a bulb tool and when i ground it and touch the defroster tab on the passenger side it lights up green but when i touch any of the grids nothing happens. Has anyone dealt with this issue or know how to fix it?

 

Aren't the grids painted? You're not going to be able to test continuity through paint

 

I have this issue with my rear window. One of the lines right smack in the middle does not work.

To test it, you'll need a volt meter. Connect the ground of the volt meter to one of the tabs on either side of the window and with the positive wire check each line from the inside of your car, while they are on. You will see that depending on where you touch, the Volt is different, so if you go in a straight line from top to bottom checking each one they should all be the same volts. If not then you have a break in one of the lines. You can buy a repair kit for it once you find the break.

Good luck.