Normal operation. When in auto the gauges will dim right before dark and during night when the headlights turn on. If you don't like how dark they are or you don't want them to dim you can adjust the brightness to MAX with the little button on the left side of the dash next to the blind spot and traction control button.
Ha, could not find anything on that Chrysler 300 with factory GPS, dimmed so much a night, couldn't even read it. But no problem in my Limited, just go to Nav under setup and set it up the way I want to.
If all else fails, read the owners manual. Really don't care for my headlights flashing and the horn beeping when using the remote, that can be switched off, can either unlock just the drivers door or all four plus a host of other things, its all in the owners manual.
All dash's that have constant back-lit displays are designed to dim when the headlights come on for night vision. What seems very dim during the day ends up being extremely bright at night. The dash and headlights used to be directly connected to each other - headlights come on, dash lights dim. On vehicles that are equipped with auto headlights when the wipers came on made it a real pain to see during the day without constantly adjusting the dimness; now the headlights can come on and the dash remain bright depending on ambient lighting. It's nice now that they are semi-independent. You cant adjust the dimness, as stated, with the button to the left of the steering wheel.