Need help, I have a 2002 f150 xlt with a 5.4 stopped for gas when to start it up nothing? Towed it home tried again just clicking from a relay in fuse box relay #1 looked in manual says that relay is for audio just keeps clicking even with the key out had to disconnect the battery? Any help?

 

That relay has nothing to do with cranking.
You have a corroded battery connection or a loose connection at some point.
Get in there and begin to check and clean connections until you get to a point that either you found it of have to look in other parts of the battery and start circuit.
Good luck.