How Instrument Clusters Work & What to do When Gauges Go Bad.
MotorWeek's Pat Goss (RockAuto.com is a MotorWeek Sponsor) demonstrates how modern instrument clusters work and explains what can make gauges go bad. He shows replacement instrument clusters by Dorman (found under "Body-Interior" at RockAuto.com) that are relatively inexpensive and often better made than the original gauge cluster.
Instrument Panel Cluster Malfunction
As you can see my 2004 GMC truck speedometer has malfunction. The dealer said it will cost between $400 and $600 dollars to replace. I look on the internet and found a special bulletin from GMC. I called GMC and they said it will only cost $120 for the labor to replace. The special bulletin will cover the part cost. I hope this can help you. Go to http://www.gm-trucks.com/forums/index.php?showtopic=70134
How to Remove and Repair A Chevy or GMC Instrument Cluster (2003-2006)
http://circuitboardmedics.com/2003-2006-chevrolet-instrument-cluster-repair / How to remove the instrument cluster from a 2005 GMC Sierra. This removal process is similar to other GM vehicles such as Suburban, Silverado, Yukon, & Tahoe. This is a complete rebuild of the instrument cluster on 2003, 2004, 2005, and 2006 GM (Chevrolet, GMC, Pontiac, Hummer, Buick, Cadillac, Isuzu, and Oldsmobile) vehicles including Chevrolet Silverado, GMC Envoy, Trailblazer, Ranier, Suburban, Tahoe, & others. Our rebuild service includes all new backlighting, new stepper motors behind each gauge, and several upgrades to protect the odometer and gear level indicator (PRNDL) from fading or becoming dim. We also offer an options LED upgrade to the backlighting with four different options: white, blue, red and green. We offer a lifetime warranty on the functionality of the cluster and gauges. Give us a call if you have any additional questions.