Cat TH580B cluster issues

Hey guys I have a Cat TH580B Tele handler and the cluster is acting up. When the key is turned to the on position the gauges will swipe and lights come on normally and the gauge seems to be functioning fine. After starting the machine the gauges still seem to be working fine and the tach idles properly. Once you apply throttle all the gauges die and go down to nothing. Once the machine returns to idle power is restored to the cluster gauges and they seem to function again. Does anyone know of a way to test the cluster? Cat says they can't test the cluster out of the machine. New cluster is $1500. Would like to confirm it's bad if possible. Thanks.