Welcome to Challengertalk Sue. This is a fairly common issue unfortunately. See attached pdf. I believe you have to either pull the radio fuse, or disconnect the negative battery cable for 1/2 hour or so.
I'm not certain which fuse is the battery fuse but looks to be fuse #37 on the rear PDC (Fuse box, under trunk liner). If you are going there anyway, the battery is there and you can just disconnect that for a while