06 ram 1500 won't start

So truck runs great. Go to store. Come back out
and won't start. Checked battery, starter, all
grounds, all fuses and wires behind d fuse box.
Power doesn't seem to be an issue but turn the key
and everything does what it's supposed to except
starter won't turn. Replaced ignition switch and still
nothing. However if I ha e someone hold key in
start position and jump the cylinoid on the starter
itwill fire up. Any ideas?