Headlight problem

[AlphaTeam]

I've got a package 6 2006 Prius. One of the headlights keeps going out. I can't really tell when or how it goes out since I can't see it. I'll notice it when I see the reflection in the back of another car. If I turn the bright lights on and off it has no effect, but when I turn them all the way off and back on the light comes back. Sometimes on long trips it will stay on the whole time, sometimes it won't. Sometimes on short trips it will go out, sometimes it won't. It is not an event I can make happen. I've taken it to the dealer and they can't make it happen (of course). ANyone have any ideas as to what is going on?

[hyo silver]

Sure sounds like a loose conection, maybe a faulty bulb. Are they HID? Do bumps in the road have any effect?

[AlphaTeam]

They are HID's.
I'm not sure about the loose connection theory. But I'm not an expert on HID operation. But lets say that it was loose and I hit a bump light goes out. Why would be turning the lights off and back on make them go back on? If the circuit was open then switching them off and on would still not make it operate. If the connection opened and reclosed then why didn't it come back on by itself?

[galaxee]

bulb and/or HID computer, probably. i believe this is the 4th time i've read about this, but DH hasn't seen one yet.

[1fixitman]

<div class='quotetop'>QUOTE(galaxee @ Jul 5 2007, 10:57 AM) [snapback]473448[/snapback]</div>

bulb and/or HID computer, probably. i believe this is the 4th time i've read about this, but DH hasn't seen one yet.
[/b]

Galaxee,
I am not familiar with the location of the HID Printed Circuit Board. It it possible that these boards are being put in places that do not allow enough heat to be removed from them? Are they exposed to any air flow or do they have heat sinks on the board somewhere? Just curious in theory if heat removal may solve the problem with this long, ongoing issue with many of the vehicles out there. If this is an issue then a small micro fan that operates on 12 volts similar to those found in electronic gear may help or solve this problem. This is all theory for now and I do not have a vehicle with this problem to troubleshoot.

D Rock

[ekarasko]

The problem with intermittent HID headlight operation appears to be common with the Prius, but is also occurring with other models. I own a Sienna with the same problem. The dealer first replaced the HID computer $1,100, then the bulb $400, and now tells me I need a whole new headlight assembly for another $1,100. This is all in three months. The service technician said "If its not working, give it a little hit with your fist." Not easy to do on the highway. The point is that inoperable headlights are a safety issue, police officers can stop you for it, and you cannot pass inspection without operating headlights. Reading the posts on this site, it is clear that there is a manufacturing defect that is contributing to the problem. You must help out by going to the National Highway Safety Administration web site and filing a complaint (www.NHTSA.gov) It will take you about 5 minutes and you will need the VIN number of your vehicle. If enough people who are having this problem complain, Toyota will likely have to issue a recall and pay for the repairs. Up to $2,600 dollars is too much to pay for working headlights. Good luck.


<div class='quotetop'>QUOTE(AlphaTeam @ Jul 5 2007, 09:06 AM) [snapback]473428[/snapback]</div>

I've got a package 6 2006 Prius. One of the headlights keeps going out. I can't really tell when or how it goes out since I can't see it. I'll notice it when I see the reflection in the back of another car. If I turn the bright lights on and off it has no effect, but when I turn them all the way off and back on the light comes back. Sometimes on long trips it will stay on the whole time, sometimes it won't. Sometimes on short trips it will go out, sometimes it won't. It is not an event I can make happen. I've taken it to the dealer and they can't make it happen (of course). ANyone have any ideas as to what is going on?
[/b]

[davidtoo]

<div class='quotetop'>QUOTE(AlphaTeam @ Jul 5 2007, 06:06 AM) [snapback]473428[/snapback]</div>

I've got a package 6 2006 Prius. One of the headlights keeps going out. I can't really tell when or how it goes out since I can't see it. I'll notice it when I see the reflection in the back of another car. If I turn the bright lights on and off it has no effect, but when I turn them all the way off and back on the light comes back. Sometimes on long trips it will stay on the whole time, sometimes it won't. Sometimes on short trips it will go out, sometimes it won't. It is not an event I can make happen. I've taken it to the dealer and they can't make it happen (of course). ANyone have any ideas as to what is going on?
[/b]

I have a 2006 Prius with the same symptoms. Today I took it to the dealer who told me my left halogen headlight had gone out at 40,000 miles (it would work if I turned the light on again - for a while. It cost $529 to repair - they have to remove the bumper to replace the headlight assembly.

[wile-e]

I know from other cars where they had one HID light that was affected intermittently the problem was at the connector going to that particular light. If you pull the connector loose you usually have a poor connection at that point. You will see some blackening on the connection because it has been arcing. I have known those who replaced the connector completely and some who bent the parts so that they touched. Much cheaper than $1100..... Of course none of these were on a Prius.....

You should probably have someone with a wiring diagram check every connection on the route.

As I sit here and think about your problem the connection may be just under the Fuse Assembly on the Prius. I looked at the underneath of mine recently due to some other problems and the connection that 'Y's out for the headlights is one that was not firmly snapped in on mine. (The assembly got melted by the Toyota shop person when I had them checking the 12V battery. The Toyota techs kept putting things back together wrong.... A month of back and forth with them till I found that the Fuse box wasn't snapped in correctly on one corner... When I FINALLY got the car back from the dealer I checked all of the connections...)

It makes some sense for the intermittent. In the case of a friend's car the little snap that held that section of the wiring harness in place had snapped off so the connector would bounce off the side of the fender. If he stopped while turning left it would blink. I imagine that this could also happen with the HID controller, but I would assume that the dealer's tech would catch that. (Most HID controllers are close to the light.)

Now you are going to make me go out and check my connections.....again!

[galaxee]

<div class='quotetop'>QUOTE(D Rock @ Jul 15 2007, 06:40 AM) [snapback]479036[/snapback]</div>

Galaxee,
I am not familiar with the location of the HID Printed Circuit Board. It it possible that these boards are being put in places that do not allow enough heat to be removed from them? Are they exposed to any air flow or do they have heat sinks on the board somewhere? Just curious in theory if heat removal may solve the problem with this long, ongoing issue with many of the vehicles out there. If this is an issue then a small micro fan that operates on 12 volts similar to those found in electronic gear may help or solve this problem. This is all theory for now and I do not have a vehicle with this problem to troubleshoot.

D Rock
[/b]

D- i completely missed this a few months ago! sorry.

we're in the process of going through pretty much everything we own and trying to minimize. included in all that is DH's store of "interesting car parts i want to take apart someday" that were well enough ignored by the end of 70 hour work weeks. iirc there is an HID computer in there. if/when he runs across it i will ask him to take it apart and look for air flow/heat sinks before it goes.

funny, he never once saw the HID light issue described here and the only burned out ones he saw in his time as a yota tech were from using HIDs as running lights.

[drmanny3]

I have experienced the same problem. I tried pulling the fuze out and replacing it and the light would work. However, the problem still occurs. I found that if I turn off the head lights completely and then turn them back on that the light will then work. I keep my lights on all the time. With the HID they run at a lower voltage during the day. I have about 30,000 miles on the car and it is still in warranty. So I guess I will take it in. I will try and wait for the light to be off so that when I drive it in they will see it not working. That is half the battle convincing others that there is a real problem.

Manny