Check chassis battery connection...the jacks run on the chassis battery....and obviously the dimmer/gauges do as well...Not only check the grounds but also the positive connections as well.
Stuart and Stella Denning
2016 Entegra Aspire 42RBQ
The 3 Bulldogs (Daisy, Sylvie and Stashie)
2018 Equinox Diesel (TOAD)