Depress Clutch all the way 
If the solenoid does not move (no clicking indicating the Starter Solenoid moved) then a sticky Solenoid or Solenoid Ground Connection. Or.....you do not have 12 volts in purple wire.
You can hot wire the starter (purple wire) when that happens to see if it is the starter or starter ground circuit. Or check that purple wire for 12 volts when you turn the key to start. If you have 12 volts in purple wire (key turned to start) it be the Solenoid is stuck or connection of purple wire to solenoid is bad. You really need someone in seat turning the key to start
with Clutch depressed.
Post 52 - Starter, Starter Relay, Wiring Harness, Battery, and Plugs Tricks