speedometer dances sometimes

[zandi]

every now and then my speedometer isnt accurate and starts bouncing around near the speed im at, it doesnt go too far just a little bouncy so u cant see how fast you're going, is it a sender unit gone bad or something? the problem goes away ever now and then, and its usually absent

[nefarious7907]

I have had a similar problem with my speedometer dropping to zero and then jumping up to speed and back and forth again. I would just wiggle some wires to see if there is a loose one on the back of your cluster.