I have a 2001 Grand Caravan ES with 185,000 miles on it. The issue I have is driving at night with the headlights on, the speedometer needle disappears between 55 and 60 mph and reappears between 65 and 70 mph.

 

You more than likely have a light behind the cluster out. I replaced all of them on the back of my Dads 2001. Its an easy repair done with nothing but a Philips screw driver and a pair of needle nose pliers. If you need anymore info, send me a message.