09 Aveo No crank, all power cuts when turn key to run starter

I have 2009 Aveo, one day I was at work and my Fiancée came for a drive at lunch. Car didn’t want to start but all of a sudden started fine. Parker the car there for the weekend. When we got back I went to fire the car up, all dash lights came on fine and as soon as I when to bump the starter, all power goes out. No lights nothing. Fuel pump doesn’t kick in, ive chased this for probably 6 months now. Starter works fine as I bypassed it and turned over fine. I found my negative battery ground not connected to the chassis, couldn’t find where it originally went so I put it by the battery tray? Car has a brand new battery that I put in my truck and has been working fine for months since. I’m lost