Incendiary

I have a 2014 E350 wagon. The rear view mirror has two circular lights on the underside. The right light has a tiny circular light next to it, while the left light does not.

We recently noticed that the right light and the tiny circle next to it are both dimly lit, while the left light is not.

Can someone tell me what these lights are for and why only 2 of the 3 are lit?

Thanks in advance. And sorry if this is a moronic question...

thefisch

The two larger circle lights should be the map lights for the driver and passenger. The controls are above by the sunroof control. The little button or hole close to the passenger side light may be the settings/calibration button for your rear view mirror compass. Check your manual for further instructions on that.

Incendiary

Thanks. I uploaded some pics to illustrate what I mean.

I am able to turn both of the lights on with the buttons above the rear view mirror, and they come on very brightly (pic 1). However, I also notice that during the day the lights are normally off, but when it gets darker the light on the right turns on but not the light on the left (pics 2 and 3). I guess this is intended as ambient lighting at night, but is this function by design (right light on only, not left) or is my left light sensor not working?

thefisch

Mine is a 2011 so it may be different. My manual (around page 303) indicates that circle near the passenger map light is for compass calibration. However, yours look like a plastic lens cover. Perhaps it is for ambient light but it seems like a poor design since the light bleeds over to the map light. What does your manual say?

Maybe others will chime in or you can ask the next time you're at the dealer.

KEY08

I don't see a left light(driver's side) in your photo, unless you are referring to the Homelink LED lamp.
The small light is an ambient only light as you have determined.

Incendiary

That's correct. There is no small light near the left map light. There is only the Homelink button.

I guess it is poor design. I was confused as to why the small light on the right was lit and why the right map light was only partially lit and the left map light not at all. It seems that the small (ambient) light is indeed bleeding over into the right map light, and neither map light is designed to be lit.

Thanks for your help, all.