Tach Gauge Problems '05 2500HD

[blime81]

Ok so my tach seems to work intermittently on this truck. Sometimes it seems right on and sometimes its way low (like it's off at idle and then barely over 1k when I'm on the gas hard). Sometimes it does nothing at all.

I'm pretty sure that the gauges must go bad in these pretty regularly judging by the amount of cluster swap options available. (My folks have a 04 Trailblazer with similar issues except theirs is speedo, gas gauge etc.)

I'm wondering if there is an easy or cheap fix for this (besides replacing the whole cluster)? When I had issues with my the 4wd switch in my '99 everyone said to replace it. I pulled it out and cleaned the contacts and it was good for another 30k until I sold the truck.

Any ideas? Thanks in advance.