Recently in my 2003 Grand Prix GT I am having trouble getting it to start. I will get in, lights are on, stereo turns on(even powers my 600W subwoofer no problem), everything electronic works perfectly, but I turn the key and suddenly everything shuts off and the key locks up. I then have to wiggle the battery cable some place between the negative and positive terminals and after the cable moves every so slightly(stays put on the terminals, just the cable moves) I hear everything power back up and the fuel pump turns on. It was only happening when I'd try and start my car before, but today I got to Chipotle and stepped out and hit the lock button on the keyfob and nothing happened. Got back in my car and sure enough all electronics were off. Had to wiggle the battery again to get it to start. The battery is only about 2 months old, if that, and this happened on the old one too. The cables are all original. The negative terminal used to be loose, so I bought a new little bolt for it and it seems to be secured now. Not sure why it would be doing this. And it's not everything single time. It happens most of the time, but sometimes it will start up no problem and no hesitation at all. It also doesn't seem like the starter to me, because ALL electronics shut off and only moving the cables directly attached to the battery fixes it. Any help would be greatly appreciated, thank you.
