If you get the click from the relay, its seeing everything it needs or it wouldn't "click". When the relay clicks, it is completing the circuit and should be supplying the power to the starter solenoid. I assume when your "jumping across the terminals" you are going from the battery to the starter solenoid post to get it to crank.

If that is what you have, I would suspect a bad wire or a bad connection on either end of the wire going from the relay to the starter solenoid. Any corrosion on any terminal on the relay is enough to cause you a no crank situation.

On one of my Dakotas I had a no crank situation with the solenoid clicking, but if you jumped across the terminals in the relay, the starter would crank. What I found was the mechanical end of the keyed ignition switch had a broken loop that was suppose to pull the rod on the starter switch to the crank position. With the loop broken, it pulled far enough to activate the relay, but not far enough to pull the starter switch all the way to the crank position. A new mechanical end for the keyed ignition switch solved the problem, but to get it I had to replace the entire ignition key switch. Gene