These type of starters can pass bench test, yet fail under load. Get a breaker bar and with the key turned off (very important because I left the key on one time and got a big bruise from the ignition kicking the motor backwards) turn the motor and listen for a clunk from the starter. If you do, then the snapring shattered in the nose and the drive stuck engaged with the contacts open so it can't engage. When you hear the clunk, try the ignition again. It may go. If so, the starter needs to be fixed, but mine did that for 3 months before I got tired of it and pulled it.