As stated, my dashlights are not backlit during the daytime with exterior lights off. I find the dash too dark. Bought the truck used, has always been this way. Lights work/dim great with headlight switch on.
2018 Peterbilt 567
Ya thats the way they are supposed to be. You can just turn on the clearance lights and the dash will light up. Should be a dash dimmer switch on the left panel.
Dealer should be able to change cecu settings so gauges are back-lit all the time.