Dear Auto board.

Once in a while, driver side headlight goes out when driving. I can simply turn off the light and turn it back, then it comes back on.

I do believe it's Xenon HID.

Bad ballast?

TIA.

Swap it to the other side and see if it continues

Hmmm good idea

I had a similar issue awhile back in an Infiniti with HIDs. There was a headlight relay where the wiring went bad over time. When it got too hot it would turn one light off, and when it cooled down after a few minutes the light would come back on. Also could turn it off and back on and it would usually come back on. Replaced the relay and it was fixed.

Thanks!

What vehicle is this on? OEM HIDs or aftermarket kit?

OEM 2008 avalon