[kalama3]

I have a 2003 LS. Speedometer, temp gauge and fuel gauge jump all around, then are accurate for a few seconds, then bottom out, then jump around some more. I have thoroughly cleaned the battery to make sure the ground was ok. Odometer works normally. Any clues

 

[Dimwaldt]

My '06 ST did the same thing, except mine started with the battery light coming on even though the alternator was putting out 13.8v. It went downhill from there. Turned out to be the BCM (Body Control Module) computer. It would have been very expensive except it was still under warranty.