I've tried everything and it's ultimately a ballast replacement that I need. The dealer is selling the whole headlight unit for $1500. Any suggestions on how to find a new passenger headlight unit? Or the ballast? I have a sedan. I accidentally ordered one for a coupe but it obviously doesn't fit. Any assistance is helpful.

 

So, I would recommend just going to a wrecker. First though, could be your bulbs. Our ballasts HATE pretty much all D2S bulbs besides Osram, Phillips(OEM), and Morimoto. Some people have had luck with other brands here and there, but nothing consistent. I went through 5 sets of DiodeDynamics bulbs before they gave up sending me free replacements and I realized the problem was the bulbs, not the car. If its one side thats not working, try throwing the bulb from the other side in there and see if it works, easiest way to determine if it really is the ballast. The ballast comes with the headlight assembly, so finding and buying it separately can be tough unless you go with ebay or a local wrecker.

Alternatively, you can buy a DEPO headlight from rockauto for less than half that price the dealer is asking. https://www.rockauto.com/en/catalog/...assembly,10762

 

Ballasts and bulbs are easy enough to replace- a hassle, but doable, plus they are interchangeable between models. There is absolutely no need to replace the entire headlamp assembly unless it is severely damaged (ie. wrecked).

What exactly are your symptoms?