what happens when the guages all go out for a min, no battery charg and then ok on 2002 Chevrolet Tahoe

the battery charges and then it doesn't, everything went out and then came back on it is the cluster in the dash or is it going to quit all together, the battery light comes on . i took it and put it on a machine, new battery and alternator was fine. puzzled

Asked by for the 2002 Chevrolet Tahoe
sounds like a bad ground or the inst cluster is going