Using a test light or multimeter check for power going into and out of the headlight and dashlight dimmer switch. The switch needs to be on to test for power out of the switch. If you have power, check for proper grounding at both switches. Do the same at the dash panel.. if there is power at the switches, but none at the dash lights, check for continuity in the circuit. This is to test for broken wires to the panel. If the wire tests good, chances are that the cluster has an issue and will need to be replaced.