[FixxxerKH202]

Yeah this is news to me, but you'll have to find the diagrams and trace the circuit then test it all with a meter.

If the clusters bad like he said some pop up on here and you can find them on eBay or through junkyards just make sure it has less miles than yours if used.

 

[FixxxerKH202]

He can rule everything else out though. What if he has a bad ground on the circuit causing the stepper motor to have an inconsistent resistance making the gauge read off? This is more likely the caus to me since GM is notorious for bad grounds.