So, I have a 2005 Prius with the factory HID's When I bought the vehicle almost a year ago up until a few days ago I was running the no-name cheap HID bulbs that came with the car from the previous owner. Finally the passenger side light flickered and burnt out one night so I went ahead and bought Philips D2R bulbs to replace both sides with. I replaced them both at the same time and initially they both worked great. But that night when I went out, the driver side wouldn't work. After some testing, I found I could get the driver side to work by turning the head light switch on and off rapidly until it would finally cause the driver side to light up. The driver side bulb color looks fine, it looks just like the passenger side. Once it's on it's fine, no flickering, no dimness, nothing out of the ordinary. Something else I noticed is the driver side will fail to light about 50 percent of the time if I drive the car, park it, turn everything off, and try to turn the headlights on again in a few minutes. But if I come out and the car has been sitting for some time, the headlights come on no problem a majority of the time. Any ideas? Bad bulbs? Bad ballast? Bad headlight switch? I never had this problem with the old bulbs, and the problem showed up almost immediately once I put the new bulbs in.
Wish I had an answer. About a year ago my lights started behaving in a similar fashion, so I kept turning them on and off until they were both on again (known trick). Then at some point they quit acting up. Of course I still look for the reflection in the vehicle in front of me (or whatever else is available), as I don't want to be that guy Had the prior owner ever changed the HID bulb(s), have no idea. Will I change out the bulbs? only after flicking the switch trick no longer works, and I haven't had to do that for some time now Did you purchase those HID replacement bulbs at a local brick and mortar store?
I actually bought the pair of bulbs online for about 80 dollars. I don't have the boxes anymore so I guess it is possible they are counterfeit. But the boxes looked pretty legit, I didn't notice anything off about them. The bulbs when they're working are actually pretty bright, much brighter than my no-name bulbs. And I did pay 80 for the pair which seems to be about the average price for a pair of legit bulbs. But who knows. Do bulbs have a break in period or something?
If you swap the ballasts first: I guess to me swapping the ballasts can rule out a connection problem or wiring issue, if the trouble follows the ballast, (my suspect). It’s most likely easier to swap bulbs, but won’t rule out a wiring or connection issue on the driver side if the trouble stays on that side.
Took a while but I ended up just getting a new bulb. Replaced the driver side bulb and now things work just fine. I haven't had a failure to light yet.
