[Lycoris]

I know I'm asking like way too many questions but the forums have been helpful.
My 2016 435i xenon headlights randomly flicker. I only notice it when I'm stopped and it's not all the time. just every once in a while. I noticed it when I'm at a red light or stopped at a drive through. it doesn't look like an aggressive on/off flickering but it's flickering. it goes away when I'm driving or turn the headlights on and off again while stopped. I didn't notice anything burnt when I took a look inside.

[Wires]

Low battery issue? If you charge up the battery does it still happen?

[Desertnate]

Does it occur when something else happens on the car like the AC compressor kicking in?

When you say "flicker" do you mean a rapid series of changes in the light, or just a one-time drop in the intensity of the lights.

[Lycoris]

Originally Posted by Wires

Low battery issue? If you charge up the battery does it still happen?

my battery should be fine. showing a good charge

[Lycoris]

Originally Posted by Desertnate

Does it occur when something else happens on the car like the AC compressor kicking in?

When you say "flicker" do you mean a rapid series of changes in the light, or just a one-time drop in the intensity of the lights.

hmmmm never thought about AC compressor kicking in. I usually have climate set on auto and when the lights flicker, it's like the intensity goes down to dim and back up kinda fast. like flickering but not completely on and off flickering.

[Desertnate]

Originally Posted by Lycoris

hmmmm never thought about AC compressor kicking in. I usually have climate set on auto and when the lights flicker, it's like the intensity goes down to dim and back up kinda fast. like flickering but not completely on and off flickering.

It was a long shot, but I only asked because I owned a Pontiac in the mid-90's whose lights would do just as you describe every time the car was sitting still and the A/C compressor turned on. On that car it was a rapid, but slow dip in the intensity of the headlights.

In your case there may be something totally different happening, but only asked in the event it might trigger a thought from someone here much smarter than I am.

[frazervalley]

Just checked out The Car Geek and it is very informative with nice before and after photos of your work. Great job!

[BBri89]

Does it only do it when it's raining or wet?


I first thought I had big problems of rain getting into the electrics, as when I was behind another car at the traffic lights in the rain the xenons were clearly flickering.

It was so bad once when we got home and it was still doing it against the garage wall, I got my wife to get out and look, and she said they were absolutely fine but there was water running off the bonnet and down the front of the headlights.

So the water trickle was actually refracting the light and causing what appeared to be a prominent flicker.



If it's still doing it in the dry, then it's clearly another problem. Maybe a ballast issue.

[Lycoris]

Originally Posted by BBri89

Does it only do it when it's raining or wet?


I first thought I had big problems of rain getting into the electrics, as when I was behind another car at the traffic lights in the rain the xenons were clearly flickering.

It was so bad once when we got home and it was still doing it against the garage wall, I got my wife to get out and look, and she said they were absolutely fine but there was water running off the bonnet and down the front of the headlights.

So the water trickle was actually refracting the light and causing what appeared to be a prominent flicker.



If it's still doing it in the dry, then it's clearly another problem. Maybe a ballast issue.

hmmmm I'll keep an eye out next time to see if it's rain. But the last time it was happening, I just turned off the headlights and turned it back on and it fixed it. super weird.

[BBri89]

Originally Posted by Lycoris

hmmmm I'll keep an eye out next time to see if it's rain. But the last time it was happening, I just turned off the headlights and turned it back on and it fixed it. super weird.

It sounds like it might be the electrical ballast then that is the problem. Is it just one headlight or both?

The ballast regulates the voltage to the bulbs because they require a high ignition voltage but low running voltage.

Looks like this:

[Lycoris]

Originally Posted by BBri89

It sounds like it might be the electrical ballast then that is the problem. Is it just one headlight or both?

The ballast regulates the voltage to the bulbs because they require a high ignition voltage but low running voltage.

Looks like this:

I'll get out next time to check. fingers crossed that I don't need to replace the ballast lol