Hi, I am not an ASE expert but here are a couple of things; to test your instrument cluster...hold down the reset button on the speedom...and then turn the key to on position- the display should say test..now press the reset button and it will show you some information...see if all your gauges respond correctly and if all the bulbs in the speedom come on..if not..try replacing the cluster..most likely will need reprogramming...now..when you say your speedometer is not working..do you mean the whole thing? or just lights going crazy and gauges going crazy?..also if you want handy information about your mini van..go to autozone and pick up the haynes repair manaul..almost all the information you will need for troubleshooting. | 
