Get the manual out and make sure you read all the info on the dash dimmer. In my sig, there is a link to the 2011 manual pdf, if you would like to look now.
On page 5-24 of 213 (pdf) talks about the dashboard illumination.
Rotate the knob to adjust the brightness of
the instrument cluster and other
illuminations in the dashboard.
NOTE
l The brightness of dashboard illuminations
can be adjusted when the headlight switch
is in the or position.
l When the dashboard illumination
brightness cannot be adjusted any more, a
beep sound will be heard.
l (Black-out meter)
The brightness of the instrument cluster
illumination can be adjusted when the
headlight switch is in any position.
Canceling the illumination dimmer
(Black-out meter and dashboard
illuminations)
When the headlight switch is in the
or position, the illumination of the
instrument cluster and the information
display dims.
When driving on snowy or foggy roads,
or in other situations when the instrument
cluster or information display's visibility
is reduced due to glare from surrounding
brightness, cancel the illumination
dimmer and increase the illumination
intensity.
5-42