Freightliner chassis? They have known problems with the wires going to the gauges on the dash. I think they have a kit that's supposed to solve that type problem. When I had an 08 Bus I had the issue with the air brake pressure gauge and warning system. All the dash gauges are on a single wire, daisy chained together. The data transmitted on the wire has all the info each gauge needs in a chain and the individual gauge picks only the info it needs out of the string. The order the gauges are hooked up in makes absolutely no difference
I dropped the dash and took all the jumpers to the various connections off and reconnected then in mixed up order. After doing that, I never had the problem again. You might try the wire switch or give Freightliner Help a call and ask about the kit if you're not comfortable doing the big switch.
2013 Tiffin Allegro Bus 43QGP
2011 Chevy Silverado 1500 Toad