[New Dad New Van]

Check for a faulty front passenger's door switch. The part can become mangled from a seatbelt caught in the door for example. It is a black rubber part on the chassis. If this is faulty and left on, the interior lights can come on intermittently, the door indicator in the dash to come on and run down your battery.

 

[dlginnc]

I would check all the ground connections, battery connections and have the battery tested for starters.

 

[gavalcar_gp]

Check for a faulty front passenger's door switch. QUOTE]
+1 on that.
Early on in the life of my van, I had some strange problems usually right after closing driver's side door. The worst was it seemed almost every dash light would flicker on/off along with the sound of a relay clicking. Dealer couldn't find anything, so I removed and actually disassembled the door switch. Cleaned contacts and made a little adjustment for stronger contact. No more problems.