2002 Chrysler T&C Alarm problem

I have a Chrysler T&C mini-van that has decided to set off the alarm when you unlock and open the drivers door. Also, it has started to set of the chime indicating the key is in the ignition and a door is open - when the key is not in the ignition. It would seem that the problem lies (partially) in the system thinking that the key is still in the ignition in this case. But that doesn't fit with the Alarm going off when you unlock the van. Anyone have an insight into this happening???? Thanks for any help!!

Whoa - solved the "ding-ding-ding" problem when the key was not in the ignition. The rheostat that controls the lighting level was the culprit. Replaced it and the problem was solved. It was indicating that the interior lights were still on when the drivers door was opened - not any other door, though. But the Alarm going off problem even when the drivers door is unlocked still remains. It's an intermittant problem so it's not easy to trouble shoot...