GPS auto lighting mode stopped working
 

For the 6-plus years I've had my car GPS screen always switches between day and night when the headlights are switched on and off. It no longer works the way it used to and will only do this if I turn on the dash dimmer function so that the numbers turn red with the lights on. I've always had the switch off so that the gauges always display white and the GPS has always switched with the headlights. I got it back from the body shop a couple days ago and they had to do some electrical with the turn signal and headlight (auto mode worked when my car went into the shop). Now it doesn't work. I'm taking it back to be checked on Monday to see if they can correct it before sending it to a Mazda shop to try to fix. Any ideas as to what the issue is? I've been told the dimmer switch needs to be on for the auto function, however, this has never been true in over 6 years of having my car nor my friend's car.

Sounds like the shop "reset" your dimmer; see if you can adjust the dimmer switch so that the gauges always display white.

I tried. The only way it stays brightly white is if it's clicked at the top setting which is "cancel" mode, i.e. where it's always been. Otherwise it turns red in some degree. The shop thinks something got reset too since it doesn't work the same. I used to think the GPS would be tied to the radio/temp stuff as those go on and off with the headlights regardless of dimmer switch and that still works normally.