Check the 5v Regulator....... The old ones are crap. My Fuel and Temp used to creep up and down with no reasoning. Updated the 5V Regulator and now they are solid. http://www.mopar1.us/instrument.html
66 Dart GT, 402 11.18:109 Best
63 1/2 Galaxie 500XL 406 4Speed 13.20:103 Best
2000 Ram
2005 Durango Hemi.