I just purchased a 2009 IS 250 and the driver side low beam does not work. I tried replacing the HID bulb, but that did nothing.

I read that it might be a fuse, so I checked the headlight low beam fuse in the engine fuse box. It looks fine. I even switched it with the fog light fuse that I know works, and still nothing.

Is there possible another fuse in a different box that I am not aware of that could be causing the low beam not to work? Also, I checked the ballast and it does not look bad.

 

how did you determine the ballast does not look bad? to make sure, swap left to right and see if the problem follows.

 

So, I just visually inspected it. And then tested it with an multimeter for continuity. Nothing. However, don’t I have to remove the entire light to test the ballast on the other side?

 

so… it was the ballast. After taking apart the headlight and inspecting the ballast, it was corroded as heck. A new one did the trick.

Hardest part was heating up the seal so I could break it… I had to use a blow dryer because I didn’t have a heat gun.

 

Those are some serious green crusties. Eric O (South Main Auto YT) approves of their detection and repair =)