Strange headlight behavior

[lotuni]

Here's the deal: 07 M35x Drivers main headlight (the Xenon) randomly turns off. When it does that, if I turn the light switch to off (from either on or auto) and turn it back on the light turns on again. I have tried many things to reproduce this consistently but am at a loss.

Here's more detail:

• The turn off time is random (sometimes it takes 5 seconds after being on and turns off other times it takes 2 days before turning off again, never the same twice)
  It has turned off while the car is parked (at idle) and also turned off during motion (this test hopefully eliminating loose connections possibility)
  I have tired the auto headlight swivel (forget the acronym now) both on and off - no difference, the headlights still move regardless if the bulb is on or off
  I have tried all configurations of the auto headlight sensitivity and auto off preferences - no difference
  It always, always comes on after I turn the headlight switch to off and back on or from on to auto (if its dark) or any combination involving the switch.
  The Daylight driving lights are always on and don't have an issue

Any thoughts??

[lotuni]

well here is an update over the last week....

The headlight now only lasts about about 2 mins every time. but when I turn it of and on again it will come on but then goes out again within 2 mins.

Could this the ballast or is it the bulb itself?
I'm avoiding going in and removing the wheel and inner wheel liner to have a look until I have a better idea.

[seldomseen]

It's most likely the ballast that's dying. But you will want to isolate the problem first by testing the bulb to see if it's burning out. Infiniti is known for experiencing premature ballast failure, which is most likely attributed to the brand they used. I had a Philips ballast that lasted more than 10 years---this is when folks were buying aftermarket HID kits. Most times when an HID starts to burn out the output color turns yellow and loses it's brightness. Just a heads up a new ballast ain't cheap and a bulb runs around $50-$100 depending on where you buy it.

[lotuni]

great!

Is the ballast part of the head light assembly or is it separate? How hard is it to replace?
It seems the only way to truly test the bulb is to take it out and put it in the passenger side, or can I take a meter an see a voltage output at the bulb plug?

Hum.... I need to find the shop manual for this. If I go to the dealer I can see this costing me $500

[Alfa95]

$50 bucks for a bulb??? Wow paid $15 for a pair.