It's been awhile since I last posted. We don't use the Buick that much...but the erratic problem did return. I connected by OBD-II computer to the car, and the computer output/values on the car shows the speed and tach always being perfect - the values increase and decrease accordingly to how the car is driven. I am thinking, as it was mentioned by others in earlier posts, that I am looking at taking apart the dash to get to the instrument cluster.
Does anyone have any links on how to remove all the plastic dash parts while trying to get to the instrument cluster?
thanks again,
Rick