I just finished having the same problem repaired on my 2000 caravan. It was driving me crazy as well. After doing all the recomended fixes (solder joints on cluster, cleaning contacts etc etc. I was no further ahead. I did find an edge on the transmission drain pan that was rubbing on a wiring harness but not quite through to the wires. At this point I gave up and brought it into a reputable shop. After 5 hrs of troubleshooting and $500 they found a white/ black wire under the battery box that was worn through and grounding out. All is well now except for my pocket book. I hope this helps someone avoid the frustration I went through

 

Welcome to DF
Thank you for sharing your story.

 

Wonder if my 2001 Grand Caravan is having a similar problem. When I put it in gear (any gear) the speedometer gyrates wildly and occasionally the transmission jumps. As soon as I start moving, it goes away. At the same time, the fuel gauge is very slow to move (takes about 15 minutes to go from empty to full on fill up) and the thermostat selector for the heater stopped working...blows cold air only.

Is it coincidence that they all happened at the same time, or are they related? Any idea how to fix them?