my rear defroster does not work. on 2003 GMC Yukon XL 1500

I had a new window put in and it still doesn't work. The light on the switch comes on. How do I troubleshoot this?

2 answers 3 comments
check wiring
I am not sure how to test it
use a test light and check to see if your getting power at the connector on the window

No power, will the switch light still go on if the relay is bad? That's my only guess
ck all wiring connections at window and did it work b4 the window was repl