Just replaced the battery on 1995 honda prelude. Alternator checked out fine. 2 weeks later came out of work and the car would not start. Battery would not turn over. Could this be fuel pump relay? How do I replace it?

When u say it won't start do u mean the starter is spinning the engine over but it wont fire up? if so then the fuel pump is the problem most likely not the relay, but please clarify the post for me about the starting problem.

To check if it is the fuel pump check at the end of the fuel lines at the engine bay if fuel comes out when cranking. You can take out the hose from the end that goes to the filter and see if fuel comes out. While cranking the EFI should be sending power to the pump to run. If there is none, then see if you can have the fuel ump directly connected to the battery. If it runs then you may have an issue with the relay found under the passenger side of the dashboard or the wirings.
If the fuel that comes out is weak, the fuel pump may also need replacing.

The fuel pump relay has nothing to do with your engine cranking/turning over. If your battery is dead, you may have gotten a bad battery, it happens. It also depends on what type of battery you got. Walmart, Deka, and advance auto batteries have some problems. IF your battery checks good, it is most likely your starter, or wiring to starter. If your battery is dead, but recharges good, you have a drain issue, you left something on, or the alternator is not putting out enough amps. You may be getting proper voltage, but no amps.