The Case of the "Self Determining" interior lighting brightness ...

Well, 2 weeks in and have 1000miles under the hood .... whilst driving this evening I noticed that the interior lighting (Clocks/NAV Display etc.) seems to have a mind of its own, drops to almost nothing to full by itself, stays full for about 15min, then drops back to almost nothing.

Now, the headlights were on Auto and were ON throughout the episode, double checked this as I am aware of the auto headlight feature, I then set the headlights to ON (manual setting) and the same "effect" is observed.

Anyone else out there seeing theis somewhat distracting feature ?

http://babyrr.com/forum/Thread-dashboard...ht=dimming

http://babyrr.com/forum/Thread-Paradise-...ht=dimming

No-one, including LR, has yet managed to provide a full and proper explanation.

(12-04-2012 08:35pm)cjfp Wrote:  No-one, including LR, has yet managed to provide a full and proper explanation.

I thought this was generally being attributed to over-sensitivity/hysteresis around twilight(?).

Well maybe, but then why don't the auto lights turn on/off too?, it appears just to bevte dash lights that adjust.

Are we saying there are two systems? One that turns on the auo lights and one adjusting the dash level?

My alfa does the same, the interior leds lighten up brighter when outside light is brighter and dim when e.g. in tunnels. The headlights stay on or off, just the interior lightning is adjusted. Isn't it something like that?

(12-04-2012 08:50pm)cjfp Wrote:  Well maybe, but then why don't the auto lights turn on/off too?, it appears just to bevte dash lights that adjust.

Are we saying there are two systems? One that turns on the auo lights and one adjusting the dash level?

There definitely are two systems (same as my other car, as it happens) as they react to the light at different times, so, for example, the automatic headlights come on at a slightly different time to the main display changing background colour to the night setting. This becomes really obvious when you enter a tunnel. (I'd guess that the interior sensor is at the top of the windscreen, and the exterior one is in the lights themselves - but that's all it is, a guess). That being the case, the hysteresis problem might only affect the interior sensor.

I'm away from the car but I would have thought that the sensor to switch on the headlights is in the windscreen looking skyward, whence comes our daylight. The sensor for the dash should be in the instruments themselves monitoring incident light on the face of them and adjusting the intensity to aid readability. Go into a tunnel and they dim, come out and they brighten.

As for the auto dip sensor, that's looking ahead from the rear view mirror and I assume it will have a narrow angle of view (but not so narrow that normal adjustment of the mirror will throw it off) to focus just on the road ahead. Quite tough to make it foolproof, I would have thought.

I think mark is correct - and gets extra kudos for use of the word 'whence'

The sensor for the auto dipping rear view mirror is the tiny "black" spot at the top of the mirror It is in fact a clear section of the mirror.
Pete Bell might be able to let us know where the headlight-on and instrument binnacle illumination sensors are as he seems to have access to that sort of info.

Ah, are we talking about the mirror which responds to lights behind you and hitch darkens (in which case I agree with Tim) or the function to automatically dip headlights when a car is coming towards you, in which case the sensor has to face forwards?