In article ,
wrote:
On Thursday, 17 November 2016 15:24:55 UTC, Dave Plowman (News) wrote:
Asking here in the hope someone has come across this and may have an
answer.

Car interior lights have an auto 'dimmer'. They do a graceful fade in
and fade out when switched on and off. On a Merc. Owner wanted some
slightly brighter lights so changed from tungsten to LED. The auto
system still does a graceful fade out - but sort of leaps to on,
rather than fading up. Later Mercs have got LED lighting which does
fade in and out OK - but it's not just a case of changing the module
which on the later cars is part of other things too.

On this model the module is stand alone, so would be possible to
modify it.

Probably. I can't imagine it being worth doing.

Not up to you - or me, come to that. It's something the owner wants.

Tungstens have zero output at near half power, LEDs have zero output
near zero power, hence the behaviour you see.

Did you miss the bit where newer cars manage it with LEDs?

--
*Sleep with a photographer and watch things develop

Dave Plowman London SW
To e-mail, change noise into sound.