Behind the battery you should see a plastic shroud (cover) that covers the fuel pump relay and the OVP relay. The relays you are talking about behind the fuse box I believe are the general electric relays for things like lights. The fuel pump relay is a rectangular black box on the passenger side behind the battery, behind the plastic cover, recessed into the fire wall....take a look you'll see
Here is a thread to help you test it when you find it...
300E won't start. Fuel pump? How to check??