Matthew Budau , Check all your fuses if all test good, you will have to look under dash and examine all the wires/plugs to see what all got cut, loosened or damaged and make necessary repairs. I hope the links below may also help, wire color codes and schematics. It could also be a problem with stepper motor behind the cluster which may have failed, last link below. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
http://www.jalopyjournal.com/forum/threads/chevy-color-code-for-dummies.343068/
http://www.autozone.com/repairguides/Avalanche-Sierra-Silverado-C-K-Series-1999-2005/Instrument-Panel-Gauges-Console-2000/Instrument-Cluster-Analog-Schematics/_/P-0996b43f8025ee59
http://www.bbbind.com/free_tsb.html
http://forums.trailvoy.com/showthread.php?t=48886