If the click is coming from the starter solenoid, it's most likely a bad solenoid, but there are some other things it could be as well, such as a faulty ground wire.
If you jump across the two top terminals of the solenoid with a screwdriver shaft, being careful to hold onto the insulated handle and not letting the screwdriver blade touch anything other than the terminals, does it crank over consistently? That will test the starter, battery, and cables while eliminating the low amperage portion of the starting system.
If It does turn over consistently when you jump across the terminals of the of the solenoid.
Then its faulty solenoid.----------
And the click you are hearing is coming from the starter solenoid? Then you have either a bad connection to ground on the solenoid, so check it for rust, corrosion, or loosening. If that's okay, then it time to replace the solenoid.
