Rear window defogger

I have a 2000 ols alero and the rear window defogger stopped working. I checked the relay and all the fuses and none of the lines on the window are brokern. I don’t know what else the problem could be. Any help Please

The electrical connector what joins the rear window defroster and the power wire from the front my be corroded.
A wiring diagram would be helpful.
You are certain the grid is complete? There is a test/repair kit for these defrosters.

If this Alero has the heated mirrors, check that the heater works in them as well as the rear window as they work off the same switch.

Can you get test leads onto the wire to see if there actualy is voltage going thruogh the wire.