Fuse A (in the PDC). It powers only the rear defroster.
Also, there is a relay in the trunk that controls power to the grid - that could have been removed by someone, or be defective.
If you haven't already, you might want to download the '02 FSM and use the schematics for troubleshooting - section 8W. Section 8W also has diagrams showing physical locations of connectors (including that relay). (FYI, the FSM refers to the rear grid as 'defogger' - that might help word searches in the FSM.)
Last edited by peva; 12-05-2015 at 09:16 AM.