[moosebrew]

2011 335xi, xenon lights

Driver side Xenon bulb shows as out on the dash. Bulb works, then goes out. Switches back and forth from working to not working while driving. Angel eye stays on when bulb goes out.

Bad bulb itself? Dielectric grease needed on the connection? Some kind of relay or switch?

What do you think would fix it?

[lowrydr310]

Originally Posted by moosebrew

2011 335xi, xenon lights

Driver side Xenon bulb shows as out on the dash. Bulb works, then goes out. Switches back and forth from working to not working while driving. Angel eye stays on when bulb goes out.

Bad bulb itself? Dielectric grease needed on the connection? Some kind of relay or switch?

What do you think would fix it?

Only way to find out is to open the light and inspect! Check the connections. Also check the ballasts for any damage - any condensation or moisture inside the housing? If all check out OK, replace the bulb.

[moosebrew]

Thanks, I'll look into it

[Nando_e90]

Could be the ballast. You can first try swapping the ballasts, the one on the right headlight to the left and viceversa.
Had similar symptoms when mine went bad. Sometimes the passenger side xenon worked and sometimes it went out. The ballast was the cause.

If not, you will have to check the inside connections as stated above, but take into account that the wiring isolation could be already cristalized and with little movement it starts to fall apart. You will need to rebuilt the isolation if so. Happened to me too lol.