It doesn't take much for the dimmer to die... it may have been on it's way out to begin with. Mine was working fine one evening, stopped at a store and didn't work for the trip home. They're not just a simple rheostat. Try bypassing it. Disconnect the dimmer and jumper the white/black wire to the white/green, if you think there may be a short in the new cluster put a 5-10A fuse in between the two jumpered lines.