Unknown damage Mazda B2600i

Hello friends,
I have a B2600i Mazda in 2007, this weekend I left the problem without problem and when I returned no longer turned on, without apparent problem I stopped working, as I just made the change of the fuel pump I imagine that it returned the problem and when checking it did not work for which I proceeded to lower the tank and take out the pump, when checking it in physical and apart, it is in perfect condition, reviewing the socket Short and a friend told me that it was possible that the relay has been burned, I just made it check and it is fine ...
the consultation is where the damage may be ... what can I check ...?
Please if someone can help me ..., thank you in advance ...

Slds ...
Tavo327