I'm no mechanic by any means and maybe someone more knowledgeable will reply with an exact solution but I would guess that you either have a faulty ignition switch or a short on one or more of the wires going to it. I would suggest also posting the problem to general tech forum and also the vehicle specific one called something like Town & Country / Voyager / Caravan that way more people will see it.
Is it optional to have the light turned off automatically when the ignition is turned off?
96 Concord ignition wiring diagram?