Prius headlight goes off after some time

HID type bulbs? If so, there are plenty of stories about quality issues with other than Phillips bulbs.

With a front end accident, there could be wiring harness issues, where one of the wires has a slight insulation fault, and is intermittent during normal road vibrations.

 

Last time I checked...any bulb OEM or otherwise needed current to illuminate, and a lack of current to NOT be illuminated.

If your headlights are illuminating and NOT illuminating, then illuminating again, it would seem obvious to me that the problem is on the current feed side of the equation.

How to convince them? Would it be possible to simply install OEM bulbs? Sometimes the path of least resistance is to play the game. Shouldn't have to be manipulative in that manner, but if they are going to say it's because the bulbs are Non-OEM, then the easiest way to show that isn't the case, would be to have the problem manifest while using OEM bulbs.

 

So tell us what HID bulbs you did install. I understand you are not eager to buy the Toyota bulbs at $160 each, but there is a big difference between installing a brand-name HID bulb, vs. the cheapest one from China that you can buy on eBay.

There are many posts that recommend suitable Philips HID bulbs that will turn on and stay on.

As to the question about why the light does not stay on, this is simple: HID works by a high voltage arc discharge that causes the light emission. The arc discharge can be started at a relatively low voltage. As the light produces heat, the gas pressure within increases and a higher voltage is required to maintain the arc.

As the bulb wears out, the voltage required to maintain the arc is greater than the ballast can provide, so the light goes out. For safety reasons, the ballast may stop producing voltage after a reasonable number of tries. Then when you turn it off and turn it back on, the arc may resume, temporarily.
High-intensity discharge lamp - Wikipedia, the free encyclopedia

 

Did not realize you had HID headlights.

You might do a search.

There are quite a few threads, as if I remember right, Gen 2 Prius did have issues with the HID headlights.

 

HID lights have a "ballast" to fire them, right ?
That ballast can overheat, trip the internal thermal protection and then re-fire after cooling off.
The condition you describe is most often caused by a bad ballast.
Could be a corroded connection too, I guess.

 

OK. If you are using this bulb on both sides of the car, and both bulbs continue to be intermittent, then the problem could be the ballast units or the problem could be bad 12V wiring to the ballast units.

You could try buying one replacement ballast and installing it, to see if that helps. Unfortunately, it is hard to troubleshoot an intermittent problem without substituting parts.

 

Not all HID Bulbs are created equal | PriusChat

 

You might pull the bulb that is intermittent and see whether it shows any of the characteristics of a fraudulent bulb. The price of $33 including shipping is pretty low for an authentic bulb.

If you find the bulb to be fraudulent, then buy the correct bulb from a Philips authorized reseller.

If you find the bulb to be authentic, then you'll have to decide whether you want to buy another bulb or buy a ballast unit.

 

I had the same problem with mine. It turned out to be the bulbs I was using. I recommend replacing both bulbs at the same with the Philips bulbs. I doubt you have a ballast problem. I bought them for under $100 a pair at Amazon here: Philips D4R Xenon HID Headlight Bulb, Pack of 2:Amazon:Automotive


iPhone ?

 

"Is there difference in "Philips" bulbs?!"

See post #11 which explains how to determine counterfeit vs. genuine Philips bulbs.

 

OK, perhaps the bulbs are OK. The car having been in an accident would open the possibility that the wires or plugs to the light in question are intermittent. Try turning on the lights and flexing the wires to see if you can duplicate the problem. Wear a glove to be on the safe side. If you don't find anything, then you are left with the swapping parts method.

 

Try replacing both bulbs at the same time with Philips. Mine were giving me fits until I replaced both at the same time with Philips. Now been 1.5 years trouble free.


iPhone ?

 

I'm not a big fan of just taking wild guesses and throwing money away on parts guesses.

Whatever the voltage is supposed to be at the bulb when running........it should be a fairly simple matter to test for the presence of that voltage, right ??

If the power is there, then you have a bulb problem.
If not, the problem is farther back up the line.
I once again suggest ballast.......because the symptoms you are having matches perfectly an overheating ballast.