My son went to a restaurant to hang with some friends, when he tried to leave his car wouldn't start. I went back with him the next night after he got off hoping it was just a battery problem, but it wasn't. We went back the next morning to figure it out. We found starter relay under the dash and pulled it out. It seemed to test fine, but just to make sure I took relay from AC and swapped....not the relay. Had to be starter, starter solenoid, or transmission safety switch. We gambled on the starter as the problem and took it out. It was an intimidating job. You have to detach a bunch of stuff to even see the starter, It was a fun job. I could do it much faster if I had to again.