2004 Nissan Pathfinder won't start

[Ricklee1]

I tried starting my pathfinder and it would begin clicking. It seemed all electronics were good so I continued trying to start it and the electronics began dying and it would only continue to click. I thought my battery was dying so I tried to jump start it with no effect. I then took my keys out of the ignition and the truck continued to click in the engine bay. And there was now clicking in the fuse box located under the steering column. The strange thing is when I pumped the brakes all clicking would stop. I determined that the main clicking was coming from the relay (horn and headlamps), I then removed the 3 relays and all activity stopped.
I have no idea what the issue could be but I am hoping I do not have to take it in to a mechanic to look at it. If you have any knowledge about an issue like this I would appreciate the help.

[benzguy95]

I'd see how old the battery is first, then id check the altenator,