94 F150 won't start - IDEAS PLEASE!

5L F150 '94
Makes clicking of starter and starter solenoid with key turn, but doesn't crank over.

new battery
new starter solenoid
alternator 6 months old
starter 1 month old
new terminals and old ones cleaned recently
tired knocking/hitting starter before starting
fuel pump engages
generally very well kept truck

starts ONLY when jumped with another car

Tried linking negative terminal of battery to engine block ground with jumper, but same clicking only (which means OEM ground from battery to chassis still okay?)

Any help/ideas would be appreciated.
Thanks

Mine is doing the exact same thing. I'm about to go out and check some stuff out on it. Will let you know what I find if I can get it running

I FIGURED IT OUT!!! My truck still has the factory battery cable that splits 2 ways from the battery post clamp. One cable goes down to the starter solenoid on the starter, the other goes to the solenoid on my fender. I checked voltage at the fender solenoid and had 12v. I checked voltage at the starter solenoid and had 9v and it dropped to .3v when trying to start. I cut off the cable going down to the starter and replaced it with a new one, which I bolted with the short cable at the fender solenoid. Also replaced the small wire that runs from the other terminal on the fender solenoid down to the starter solenoid just to be safe. After everything was hooked up I gave it a shot. Started right up. Ya!

the cables will get corrode on the inside over time.