Gauges are not working

Start ripping it apart. I guaranty it will be the last place you look.

afidel Start at the dash fuse box. Use a flashlight to attempt to follow the wires. It will not be fun.

I've found the wiring diagram for the chassis but it doesn't have physical locations for any of the connectors or grounds. Not sure if there's an equivalent of service data for RVs that would include that or not, might call a mobile tech or RV service manager and ask.

Thank to everyone who has taken the time to reply. Still no resolution but if it is a grounding issue where do I look? BTW my radio also works, but no sound.....

I'll support the Ground as 1st guess.. #2 and 3 are a Fuse (Marked gauges likely 5 or 10 amp) and a plug fell out...

True story: Radio in my motor home was very "Bump Senistive" the radio clearly worked but no sound from the speakers.

Well after many hours of pulling hair out.. Found the idiot did not plug the plug in all the way.. Pressed on it and click-click 100% operation. (the clicks were the plug's latches latching).

check the grounds

My first guess would be a ground issue, but that's pure guesswork based on watching lots of automotive troubleshooting videos.

Our precious coach (Freightliner chassis) did that twice. Scared me. I turned it off and shut everything down, waited a few minutes and restarted.
The coach had been setting for a few weeks both times