Howdy y'all,

I'm having some trouble with the interior lighting on my 2017 E300, I usually like to keep the automatic lighting (or the "welcome" lighting as you might call it) switched off with the overhead switch, so that the lights don't turn on when the doors are opened/the car is unlocked. However as of recent, I have noticed that the switch doesn't seem to remember the position it was in, or the setting doesn't seem to save. For example, I unlock the car and the lights turn on as I open the door. I get in and turn that setting off with the overhead switch, and it turns the little red indicator light on that says this has been saved. When I get out of the car, the lights do not turn on. However if I leave the car alone for awhile, 30-40mins, when I return the interior lights again turn on.

One thing that I should add, and the only thing I can think of that has changed since this issue has started, is that I installed a hardwired dash camera to the rear fusebox (in the trunk) utilizing an add-a-fuse (which retains the original fusebox fuse and basically splits the power that comes to that fuse location). I installed the dash cam wiring to the "ambient lighting" fuse, in the rear fuse panel, number 417. To my knowledge this fuse runs the ambient multicolor lighting, but if this is not the case and could be causing the problem, let me know. Everything else, including the interior lights, ambient lighting, etc. works as it should, so I can't sort out why adding the dash camera has caused the interior overhead lighting setting to not be saved.

Never had this trouble with my 2014 E350 - the interior light button was a manual one.

Thanks y'all!

 

Have you tried moving the dash cam connection to another fuse block location such as 414 TV Tuner or an empty location such as 415?

 

I don't know if i am technical enough..but why would you NOT want the interior lighting to turn on when u get in?! It's so nice and basic to have it right?

Also look at the car settings..

 

There are many reasons to keep the vehicle in "dark mode" such as not disturbing others and when doing surveilance. Many times I've sat in my car at nightwatching for a neighborhood vandal/prankster.

 

I have not, though I don't have the TV tuner, and the empty ones don't have hot power I don't believe. Correct me if I'm wrong on that one. I might have a moment later today to take a look, I'll try moving it to a different place that does have a hot and see what happens. I just can't seem to work out how adding the camera would cause the light to not save.

I prefer to keep it off; I work nights and find the ambient lighting provides more than enough interior light for me to see what I'm doing. I don't like to silhouette myself in the car every time I open the door. I have all my windows tinted and it defeats the purpose a little bit if the lights come on every time I open the door. I am also in law enforcement and we always keep the interior lights off on all our vehicles to prevent being silhouetted by the interior light, and I started doing the same thing in my personal vehicles about 8 years ago so now I'm just used to it.

I did take a look in the car settings and the setting for interior light shutoff delay is at "off" though I suspect that adjusts how long after exiting/locking the vehicle the interior lights stay on, which would be irrelevant if the system is manually turned off anyways...