Tranny wont shift into overdrive

Hi there,
I recently bought a used Dodge 1997 B2500 Conversion Van with 122K miles on it. Beside a rusted rain gutter and spare tire mount the tranny will not shift into overdrive. There is a control button (circled D) on the dashboard with a control light next to it. The light will stay on even when you push the button. I have no manual yet at all for this Van. The previous owner says that he got a new tranny installed and after a couple miles driving it the overdrive went bad. It shifts perfectly smouth but it will not go into overdrive.
Does anybody have an idea of what the problem is? I apologize for my spelling. I am living in Germany! Thank you all for your help

I'd say it's a blown fuse, broken wire, or the OD solenoid is no good.

This was covered about two years ago in the Ram Van forums here. Do a search for the tranny OD, the information should still be there to fix this.