Voltage is supplied to the rear window heating switch only when the ignition is on. When the rear window heating is switched on, an orange indicator lamp lights up in the switch button.
If the heating element is damaged, replace the glass together with the heating element.
Helpful advice. There are special kits on sale for restoring the heating element threads of the rear window heating. Instead of replacing the glass, you can try to restore the heating element threads, following the instructions attached to the kit.
[The text is copied from the online portal: VAZBOOK.RU]