So my mom's 01 Cavalier has been having problems starting for the last few weeks. Last week the check engine light came on, the scanner said it was the crank position sensor. We bought it and it had to wait to be done cuz I was heading out of town that night. The same day I get back her car won't start at my brothers house. They fingered it was the 4 year old battery and jumped the car. They got to walmart and bought a new battery and again it wouldn't start. She then had it towed to my house, I finally got the new sensor in and it all put back together. Went to start it and it still won't start, but its the strangest thing. Ok you put the key in and in the on position and everything works gauges, radio, lights, everything. When you turn the key to the start position everything died gauges, lights, radio, everything. theirs no clicking or any noise that would suggest a dead battery or solenoid. I have never seen anything like this so I'm at a total loss here. A friend of my mom's said to hit the starter with a hammer and see if it will let me start, but that honestly doesn't sound like (at least to me) a bad starter would do all that.... but any idea or help is greatly appropriated

So it turns out it was the starter.

Ya it sounds like a starter. Haha good thing you found out.