Dimmer Dial

Sounds like it is working correctly. When it is clicked up the dash lights will stay on their brightest setting even if you turn the head lights on. Hope this helps.

 

I notice a change, but it's not that dramatic. You may be best suited to adjust in the shade or at night when the display will be dimmed with lights on so you get a better idea of the result.

 

could be a bad switch. before changing it, i would ask to observe one at the dealer.

 

It's funny in my '10, which illumination circuits go through the dimmer and which don't. For example, most of the switches/buttons on the dash/center stack do, the ones on the steering wheel and doors don't, the little roof LED that shines on the shifter doesn't, those are all constant brightness. For your '13 they might have changed some of those details.

The dial you turn for brightness isn't really the dimmer itself, it is just an input to a computer. On my 2010 again, I think the actual dimmer (that is, circuit that makes a changing voltage based on how you set the dial) is built into the combination meter for whatever reason. (I guess that makes sense since the combo meter itself is also one of the things that responds to the dial.) For the other lights it controls, it is on the ground side (that is, the LEDs in dash switches, etc., are sourced from +12 volts through the tail relay and fuse(s), and return to ground through the dimmer-controlled pin on the combo meter).

The other lights that are constant brightness simply get power from the tail relay/fuses and return directly to ground. So if you're looking at the illumination wiring diagram on techinfo, you clearly see which ones are which.

There can be other components in the car that respond to the brightness you set, even if their light sources aren't literally returning through that dimmer pin. That's because the combo meter can also announce your dial setting over the communication bus(es), and other components can listen to those announcements and respond.

It can be a bit bewildering and makes a lot more sense with the wiring diagram open on techinfo.

-Chap