From you picture, it looks like you may have a mid-2000's Monaco? Our '06 Dynasty has a rectangular cover on top of the dash that gives access to the back of the instrument cluster. You might find the "hot" connection on the voltage gauge, and see if voltage is present. I've had some luck troubleshooting various problems behind the instrument cluster.
You might add your coach year and model to your side bar info. You may be more likely to find the right person to be able help you.
Jim & Angie, Boise, ID
2006 Monaco Dynasty Countess III
2017 GMC Acadia Denali