Press and hold the MENU key while powering the system up. Touch Backlight to access the display backlight settings. There are a few settings that will be of interest here in this case.
Backlight Input Source – Can be set to Manual, Photocell, or Lighting Bus. If set to manual, the backlight intensity (display brightness) can be set from 0-100%.
Default Input – Can be set to Manual, Photocell, or Lighting Bus. This controls the backlight mode that will be active each time the system is powered on.
If you choose to use the photocell input, review these settings as well:
Photocell Brightness–Sets the minimum and maximum brightness of the display backlight based on the photocell output.
Photocell Time Constant–Adjusts the speed (in seconds), that the brightness level responds to changes in the photocell output.
The Photocell brightness is an important setting to doublecheck. With Current Input
set to Manual, adjust the brightness of the display to the lowest brightness level you feel comfortable with in bright lighting conditions. Program that value for the Light Sensor Brightness
Here is a link to the latest revision of the G3X Touch Installation Manual
. All of this information can be found on page 35-127.
Let us know if you have any further questions.