1992 Plymouth Voyager speedomeitter

My 1998 voyager did this and you can either grease the speedo head this is not easy and can create inaccurate speed reading unless you are handy at small part repair like watches or clocks or what I did is go to the junk yard and get an instrument cluster from the same kind of van (inspect booth and make sure it has the indicators as yours like cruse rps and trip since some of the vans have this in another cluster panel
if this all fails check all the wires going into the plug that connects the panel if ok check the ground and other wires going up to the panel they are located on the drivers side just above the pedals you will see a few screws a cover will fall after unscrewing and expose the mice love to bite thru and hang out since this area stays warm.