troubleshooting rear defroster on 2002 Buick Rendezvous

My rear defroster appears to not be working. I change the fuse and with no results. How do you troubleshoot and repair the defroster?

Asked by for the 2002 Buick Rendezvous
Buy a cheap test light and with the defroster on connect the tester to ground and touch the grid by the wire connectors- it should lightand if it does the grid is bad. If not more in depth testing will be needed. Good luck, Greg
Thanks for your help!