My 1998 grand caravan AWD has starting having a problem with the gauges.
The ASB light comes on,then the speedometer goes to zero, the temp gauge goes to cold, then it goes back to normal, back and forth till shut off. If it does not do this at start, it won't. If it does, it will cycle on and off till car is turned off. everything still works fine including speed control.Any ideas? Larry

 

Could be as simple as corroded or loose battery terminals. The electronics are sensitive to low erratic power. Could be the very common 3rd generation cracked solder joints at the instrument cluster connector. Smack the dash above the cluster. Does anything come back to life?