I have a 2001 Grand Caravan with a really off the wall problem. About 2 months ago, the speedometer started going crazy when the car was in gear but not moving. As soon as moved from Park to any gear, it will gyrate wildly and occasionally peg against the post. As soon as the car starts moving, it goes away, only to resume again when stopped at a light or stop sign. (The car does surge on occasion as well.)

At the same time, the gas gauge started acting erratically, taking about 15 minutes to move from empty to full when I fill the tank. Also, the thermostat selection for the heater went out, so I can't go from cold to heat.

I tried cleaning connections to the battery and to the computer, but to no avail.

I don't know if the problems are related-they all occurred at the same time-but with the exception of being electrical connections in the dash, don't seem to have much in common.

Please help.

 

Take a closer look at your battery connections for corrosion and security. Not only at the post connection but also where the battery cable is crimped into the post connector, ESPECIALLY where the smaller red cable is crimped into the positive connector. That small cable connects to the IPM (fuse panel) and distributes power to all the vans accessory circuits. You may be seeing the first signs of it coming loose. Check the connection at the IPM too.

You can test the instrument cluster by holding in the odometer trip buttons then turning the key to on/run. After a few seconds the instruments will cycle.