Dimmed Backlit Dash and Radio/HVAC Lights

[EddieC]

Right, the dimmer knob (or shaft) works day or night. At the end of the rotation the dome lights turn on.
My problem is that the dash lights randomly dim themselves without my touching the dimmer,
When I say randomly, it's just that. It could go many days and then dim and come back to the setting 5 or 10 minutes later. It's not like it's constantly flashing dim and bright.

 

[mikez71]

Just checked mine. No dim at all in the daytime.. What would the issue be?

 

[PPV_2018]

Do you have anything on your dashboard? I’ve found with other vehicles that an obstructed auto-headlights sensor by means of a dashboard cover or even dark tinted windshield can cause dashboard lights to do some weird things including dimming all the cluster and control lights in the daytime intermittently.

 

[Doubeleive]

dimming is usually affected by the sensor on the forward part of the rear view mirror on drivers side
put your finger over it and the lights will dim
most likely would not be the cause for flickering or any other weird stuff though, unless you had a air freshener or a sticker or something obstructing it

 

[mikez71]

i have a dashmat now, so the dimmer is more active, but daylight mode the dimmer does not dim. Only in night mode...???

 

[Doubeleive]

i have a dashmat now, so the dimmer is more active, but daylight mode the dimmer does not dim. Only in night mode...???

it doesn't do much at all in the daytime maybe you just are not seeing it, try using a piece of cardboard to cover the radio or cluster and adjust the dimmer

 

[mikez71]

I will check again tomorrow, -BUT- if it's that hard to notice, then I don't think that's what the OP is experiencing.
If he is seeing much dimmer backlight in the daytime, which would not be achievable with daytime dimmer.

From what I can tell looking at wiring diags, the sensor in the mirror maybe for dimming mirrors, and the solar/ambient light sensor in the dash controls daytime/nighttime.

Either way, I know the ambient light sensor controls the dimmer in my 2012...

 

[Doubeleive]

I will check again tomorrow, -BUT- if it's that hard to notice, then I don't think that's what the OP is experiencing.
If he is seeing much dimmer backlight in the daytime, which would not be achievable with daytime dimmer.

From what I can tell looking at wiring diags, the sensor in the mirror maybe for dimming mirrors, and the solar/ambient light sensor in the dash controls daytime/nighttime.

Either way, I know the ambient light sensor controls the dimmer in my 2012...

you are thinking of the rear mirror sensor, it has 2 sensors one you can see when look in it and one on the (backside) "front" facing the front window.
the one you see when looking in the mirror is to detect headlights behind you and dim the mirror and drivers side mirror.
the sensor in the dash is the "sun" sensor it controls the hvac and headlight activation, when the headlights activate dimming also activates

 

[mikez71]

*Maybe* why my dimmer doesn't work in daytime..
My auto headlights are disabled.. (Autosync BCM programming)


Or not, looks like this guy had the same dimmer behavior..

Dash light dimming during the daytime?

09 LTZ - is there a way to turn off or dim the damn dashlights during the daytime? The dimmer only works when the sensor on the dash turns on the lights? Thanks

www.tahoeyukonforum.com

And I don't remember them ever dimming in the daytime...Weird

 

[Jetskier77]

Mine did the same exact thing... randomly going brighter, dimmer, etc. It would often be fine for weeks or months at a time, then go wonky. Replaced the combo headlight/dimmer switch and problem resolved.