My 2016 Chrysler 200 rear defrost not working even though when I push the button to turn it on the light does work, I have checked the fuse & it is fine. I checked the rear window for loose wires/connections but found no visible wires/connectors. What else can I check?

 

You'll have to remove the trim around the window to reveal the connections. Check to see if there is voltage at the connections on the window when you press the button. If there is voltage there, but the grid doesn't work, then it's most likely that one of the connectors glued to the window has failed. There are repair kits you can buy with special conducting glue to repair the connection. Auto parts stores carry the kits.