Pontiac Repair: 2000 Pontiac Grand Prix, pontiac grand prix, 3800 engine

Question
i have 02 pontiac grand prix 3800 engine that overnight something drains the battery whereas when i get up the next morning the car is totally dead won't start at all and key locks in the ignition. the batter is OEM of 630 and tested to be a good battery. once the car is jumped off or batter is charged the car runs and starts through out the day until it sits overnight at times

Answer
Hi
Your vehicle has a "Parasitic drain" or a current draw.
The best advice is to take it to a good automotive electrical shop, and have them locate the draw source and repair.
They'll attach an Ammeter in the system. check the draw and then unplug each fuse and watch the ammeter until the draw disappears.
From there you'll need to find what loads are on that fuse and then unplug or unhook eack load until you can pinpoint what component is drawing battery down
I hope this helps.
Good luck
PAwl