Happened to me after pulling motor to do midshaft and motor mounts this summer. It was the ground wire.
Check for a good charged battery first.
use some jumper cables and jump from battery ground to someone where on the engine. Just the negitive side of the cables to get a good ground. Then try to start, if it turns over you got a ground issue.
You can also pop the starter positive cable off the starter, hook up a meter to the lug that is now off the starter. when you press the start button you should see 12 volts. If you do then your starter relay is good, and you should look at grounds, starter. If you dont have a good 12 volts then I'd look into poor connections at the starter relay in the ebox or bad positive wires.