Windstar Interior light issue/ battery drain?

I have a 2000 ford windstar 3.8 and to no suprise have another issue with it.

I have been experiencing battery drainage problems. If I don't drive the van for a few days the battery will die. Someone said I have a parasitic draw or something like that. Today I noticed something strange. Due to this drain I have shut off all interior lights and even turned off all the gauge lighting as we don't do night driving much. When I open the van doors the interior lights don't light up. This morning my wife goes to open the drivers door and all the interior lights came on. "Van was off"

She shut the door and re-opened and this time they didn't come on. She goes to the store and opens the sliding side door and it happens again. I took a multimeter and tested the van and I noticed when I touch the positive and negative terminals of the batter the headlights come on. Again van off. I'm getting a full charge from the driving. Does anyone know what would cause these issues? Or have anything like this happen to them? I cleaned the battery terminal and they were clean nothing bad. Just alittle stumped.