Rear Defroster help

Hello,
My G/F has a '98 Buick PA and the rear defroster has quit working. The fuses are OK. The light in the controller comes on when you press the button. The coil in the glass appears to be OK. I understand there is a relay under the rear seat. If I pull out the rear seat is the relay easy to find? Is there anything else I should look for as a potential source of the problem.

Thanks in advance for your help.