1994 Chrysler Le Baron deck ajar

Have you checked to make sure the wiring connector to the switch on the trunk lid hasn't come unplugged or damaged? If it has, repair it. If not, the switch will need replaced.

If you are driving and the deck ajar lamp is illuminated you should make sure your deck lid (trunk) is closed. If it is already closed then you can repair or replace the problem with that circuit, or live and drive with it not operating properly. Usually the switch goes bad in the latch.