My 1993 Jeep Grand Cherokee's fuel pump is not receiving power I tried another fuel pump didn't work What could be wrong?

There's only two things it could be--assuming the fuse is good (you checked this before you dropped the fuel tank to change the fuel pump), there's something wrong on the main relay board. Pull it (not sure where it is because I'm not a Jeep guy, but it's usually very close to the fusebox), resolder all the connections and reinstall it. These relays get very hot on all cars, and the solder connections fail. Resoldering usually fixes it. easier than that .... is your security system enabled... what I mean is .. when you try to start it are you getting a flashing security light on the dash, if it is, cycle your keyless entry and try again, part of the security system is to cut the power to the fuel pump.