DerekACS

Very doubtful. Upon engine shutdown, my car makes the same humming sounds regardless of whether the AC has been on or off.

BeachBunny

In my experience with a lot of night time driving, I got approx 9 years out of the Xenon bulbs in my Infiniti. Both needed replacement within 4 months of each other.

On the LEDs I worry about moisture damage and progressive dimming of the diodes

uruime

Mine does the exact same thing. Also when I open the trunk.

Mud

Interesting.... I noticed that same type of noise in my non-LED lit car, opening the hood to listen, there is a small pump attached to the coolant reservoir that was the source. I need to track the hose routing a bit further but it appeared that this pump was moving coolant thru a small hose to "somewhere". Runs for a minute or 2 then stops, but I'm not sure it does it under all circumstances.

jdthor

I just took delivery on an AMG E63 and love it except..........that buzzing or humming or whatever it is behind the headlights. It isn't loud but it is annoying. It goes away when I lock the car. It comes back when I unlock the car. It is a mystery to me, and apparently to lots of other owners as well. I will try to get an answer from the MB shop supervisor next week when I see him to ask about how to remove that damn center headrest in the backseat.

Corpus Frisky

My 2015 E250 also has this LED headlight hum issue, but in my car's case, it can be fatal. Two times I have had the battery drain completely to the point where the car needed a jump start. A few other times it has been on the same course, namely the humming would go on for an hour or more before I would notice and intervene to stop it to prevent the battery from dying. To make it stop, all I have to do is start the engine and then turn the engine off. The fans stop running within a couple minutes of doing this.

But based on this thread, and other internet searching I have done, my issue does not appear to be common. The dealer has been unable to help me. Apparently no fault codes show anything to be out of normal. And I have not been able to find any reliable method of triggering the behavior. It's very random, and very occasional. Most times it stops within a couple minutes of parking the car, as others report. So I guess I am stuck with this issue to the day my car is out of warranty and beyond.