Question about a 94 plymouth grand voyager dead battery problem?

anytime any of the doors are open on my van for more than a 10 minutes (like the back hatch) it drains the battery and it does not want to start. I have replaced the alternator and the starter and my husband drove the car to work a few hours ago and went out to start it and absolutely nothing we have replaced the battery the car will start up fine it it gets a jump. what could be causing this? to make the battery drain so quickly?