What’s causing my gen 2 Prius right headlight not to turn on sometimes? I’ll have to turn off and and on a few times for it to turn back on. I changed the bulb it worked perfect for a few months then does the same thing again. I even used expensive Phillips bulb. iPad ?
The failure mode of HID headlights is that they work when cold but not when hot. Often this makes them blink, but it also means they work on a cold start but not once you get running. Sounds like you need another bulb. High-intensity discharge lamp - Wikipedia
Makes sense it always works on cold start. The odd thing is I had the car for 5+Years and the left headlight hasn’t gone bad yet. It’s only the right one that’s gone bad 3 times. I thought there was something I can do to prevent it from failing prematurely again. I’m sure a new headlight would fix it for a while. iPad ?
I never had my HIDs go out but I only owned my Gen 2 three years before a Semi ran a red light. The article mentions the ballast, and some owners do find the bulbs die faster on one side or the other. While I have not tried it, here is the best tutorial I found Toyota Prius: How to Replace the HID Ballast/Computer/ECU - PriusDIY.com
Swap the driverside to the passenger. And passenger to driverside. Test (few days) and verify if the issue follows the bulb or stay with the original headlight. Pause from buying any other hid bulbs till you try the above method. hope this helps
