Where is the fuel pump relay on a 2004 Corvette?

It is located in the underhood fuse block. Refer to your owners manual or the fuse block cover for an image view and exact location within the fuse block.

Also note that if the contact side of this relay does not have power, check fuse 13 (20A) in the underhood fuse block. You should see power on the contact side of the relay when the key is cycled on and the engine is cranking.