The Passsenger (right side) Headlight is flickering and barely shining. Obviously its about to go out. Is this a bulb? The whole assembly is about $1,200. Any ideas, Suggestions, Comments?

How can I tell if it is the balast?

 

If it's low beam, most likely the bulb. HID bulbs last a long time, but they don't last forever.
I would replace the bulb first. If it still flickers after that, then you need to replace the ballast.
It could also be a poor earth connection as your high-beam on that side doesn't seem as bright as the other side either and that is a normal halogen bulb.

 

Swap your bulbs, If issue remains, then it is probably your ballast. Lexus did a poor job on sealing ballasts and you will probably find moister inside. When you have the bulb out you may want to run compressed air inside the headlight to dry out the moister and then seal edges with silicone.

 

Thanks. I tried a different bulb and it still had the flicker. What yall are saying makes sense. Looks like moisture not just in the headlight assembly, but also in ballast itself.

I assume the LEXUS OEM Computer Light Control Part is the same thing as a ballast.

 

https://parts.lexus.com/p/Lexus_2005...596750020.html

roughly $30

I went with an Amazon version. Sorry , I don't recall which one. Still holding up after 3 years. I did seal the edges and any possible water intrusion places with silicone prior to installing.

 

Is that condensation / moisture buildup on the inside of the lens, or the outside?

 

The moisture is on the inside...the headlight has a little bit of a gap that lets it in. Also, water comes from behind the headlight from a space missing in the fender well.

 

Should I pay the $300 for the computer light control balast from Lexus or try the cheap one from Amazon?

 

I used the cheap one from Amazon, but make sure to use a good quality sealant like Morimoto butyl rubber (can find on Retrofit Source)

 

Need to fix that leak for sure, that will only cause future headaches with any electronics in the headlight housing.

https://lightwerkz.net/collections/build-materials <---plenty of good accessories in this link from @LightWerkz that can help the issues your having, even some silica gel packs that can absorb moisture inside a housing.