NISSAN V-16 '96 ELECTRIC FAILURE

Hi, my problem is that I have a 1996 Nissan V-16 and the fuel pump isn't activating when I turn the ignition on. I replaced the relay, but there was no improvement. A mechanic suggested I remove the relay and replace it with a jumper wire between two of the relay's connections to see if the pump would activate. I did the test, and when I turned the ignition on, I heard the pump, but after about 3 seconds, the fuse blew.
Why does it not work with the relay connected but it does with the jumper wire?
What can I do to fix it?
I hope someone can help me.

If you're making the connections correctly and the fuse is blowing, your problem is the fuel pump. I imagine you're shorting the ignition voltage to the relay because the relay's input comes from the battery. If the pump started when you tried to fix it, you can check if the computer is activating the relay, because the ECU only activates the relay when the ignition is turned on for a few seconds and when the engine starts. The pump should draw less than 5 amps; I don't know the exact figure, but the highest draw I've seen is 4.3 amps for a pump that was working perfectly.

Try your direct pump with a battery and see how it behaves, if you do well look for a contact cable put a 25 or 30 ampers fuse and try a few days how it goes.