Dash gauge lights not working

[Coach]

Hey guys, electrical is not my strongest, so I am looking for some help. My dash gauge lights don't work. My headlights, taillights, dome light, dimmer, turn signals & indicators, hibeam and indicator as well as the heater panel lights all work, just no dash gauge lights. The fuse is not blown either. I am thinking it is a bad headlight switch, but not sure. I have a multimeter, but not sure how to test the switch or other areas that may be the problem.