2002 2500 6 spd, got the cutting out part fixed. but the erratic tach is still there. Some times the tach works as it should, then it will drop to zero, or will just stop reading and just hang there. Now while driving it yesterday I had the temp gauge peg on me, check gauges light came on and the temp gauge went back to normal. Did the cluster self check, all is normal. Grounds are good, could the cluster be going out, or keep looking for a bad-dirty connection?