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


NT