Battery Power Comes Back on When I Open the Car Door?

Hello all!
So two or so months ago, I had the battery replaced in my 1999 Saturn SL2. About two weeks ago, something strange began happening, but only in the morning when I went to leave the house for work. I get in the car, turn the key in the ignition, and the car won’t start–the clock and dash lights will come on for a split second, then go off. I’ll try again, and this time the clock won’t come on, the dome light won’t come on–it’s as if the battery is completely dead. Here’s the strange part: when I open and shut my car door, THEN the clock and dome light come back on. Same thing with my keyless entry: after I try to start the car and it won’t start, keyless entry doesn’t work. Then, I open and close the door and the keyless entry suddenly works again. So generally I have to go through this process of turning the key in the ignition and opening and closing the door for about 5 minutes. Then, the car will start as if nothing happened and it will be fine for the rest of the day. No matter how many places I travel, how many times I stop somewhere and turn the car off, it always starts when I come back. It’s only in the morning that it does this. Occasionally, I’ve been able to go 2 or 3 days without a problem (i.e., it WILL start in the morning). Today, though, it took a good 10 minutes to start, and I’m worried some day soon here it’s just not going to start at all. Does anyone have any idea what the hell is up with my car? At this point, I’m starting to think it’s been possessed by a wily demon…

Your car is possessed, but not by a demon but a gremlin. This gremlin can easily be removed by checking your battery connections for corrosion and tightness. Once I have problems as you described, I will use my battery brush, clean both ternials and clamps, and make sure the connectors don’t move when I wiggle them. You need to replace any battery connector that will not tighten.