Welcome to the list!
Make, model, chassis, year???? Could be a fuse, loose wire, etc, etc, etc
On my '03 Winnebago Ultimate Advantage on a Spartan Chassis, I have lost apx 1/2 of my instrument cluster lights a couple of times due to a connector coming loose on the back of the dash. My dash hinges up for easy access, and last time it came loose I added a piece of tape to the connector to help it stay in place.
Paul (KE5LXU) ...was fulltimin', now parttimin'
'03 Winnebago UA 40e / '05 Honda Odyssey toad