They may not be damaged where you can see them. If you have 12v applied at the left hand side of the element, then either the ground is not connected, or there is a break in conductivity within the element at the connecting points. Disconnect the right hand side of the element and test for continuity to earth from the lead. If it is good, then go to the left hand side of the element and look at the connecting tab to element. You may have a dry joint there. Test for continuity accross the element via the connecting tabs. You could try reflowing solder back to make the connection good, otherwise, remove another rear window from a scrapped car and fit that one.
